This is kind of hard to buy when one of the core features of DDN chargen is the backgrounds and specialties, which are direct expansions of 4e's backgrounds and themes.
I mean, there are precious few things in Next that are direct transfers from any edition. Everything's been tweaked a bit, changed, expanded. Backgrounds/themes become part of the core chargen process. Combat Advantage becomes Advantage/Disadvantage. At-will spells are pretty much like 4e. Everyone says, "Hit Dice healing aren't really Healing Surges." Fair enough. But they are far closer to 4e Healing Surges than anything from any other edition. The very idea of short rests that can restore HP is a 4e innovation. And surely you didn't miss the folks complaining that 5e includes doing damage on a miss? How about casters using Intelligence or Wisdom for spell based attack rolls? How about finesse weapons that allow rogues to use Dex for their to-hit bonus, without spending a feat?
At-will spells are limited in DDN to 'cantrips', though admittedly they have expanded the definition of what a cantrip can be to a point where they do include something like an at-will 4e power. I'll yield on that point, it was certainly true that many classes in pre-4e days had effectively at-will 'powers', but DDN is closer than previous editions to 4e on that for casters. Still, there's no consistent power system, so from my perspective it is ironically almost as much undermining consistent class mechanics design of 4e as it is introducing a 4e-ism.
Going on from that to the "[things are] tweaked a bit, changed, expanded." The at-will/cantrip thing is a good example of it, yes. I can understand why cantrips can be considered a '4e-ism', but OTOH they are still not part of a consistent class mechanics, so I hope you can see how from my perspective, where that is a high value consideration, they're not a lot like the 4e equivalent.
As for other stuff, it is hard to call all those things 4e-isms. Yes, they are present in 4e, but the terminology and use is often fairly different. Similar things existed in 2e and 3.x as well, again with similar but different terminology etc. 2e had kits, 3e has PrCs, 4e has backgrounds and themes, there are probably other things in 3e as well, I'm a bit weak on all the options there.
Yes, some spells in DDN have attack rolls, this was also true of 3e and they got stat bonuses there too (IE touch attacks and such). I don't see where this is uniquely a 4e-ism. In fact the innovation in 4e was that ALL spell attacks were purely attack rolls against defenses, an architecture which allowed a great deal of simplification and added consistency to the core rules in 4e. This is no longer true in DDN where spells seem to rather arbitrarily require an attack roll, a saving throw, or even both.
I'm not sure I understand how short rests are super unique to 4e. They were never exactly codified before 4e, but parties always 'took a break' after a fight and cracked out their healing/restoration/utility magic as needed. DDN hit dice are again a BIT like Healing Surges, but they are barely recognizable and serve a different purpose. Again, I agree that it isn't always easy to draw exact parallels, its OK if we see things a bit differently here, but at least I think you can see where I'm coming from here?
Advantage? Slayer? Backgrounds? Bloodied? Warlock, with encounter powers even? (You did say "any", not "current".) At-will spells? (I'm not sure you can get much more 4e iconic than that.)
I think the message is clear that they're working on stuff that has history they can refer to throughout D&D's history. So, yes, that means 4e classes and races are going to come later. I can certainly understand frustration with having to wait. I don't think having to wait = anti-4e.
There have always been bonuses for 'advantageous situations" (in AD&D for instance a shield could only block certain attacks and rear/flank attacks got added bonuses, as did surprise attacks, etc). Giving this a specific label 'Combat Advantage' may be unique to 4e, I'm not sure as I am only passingly familiar with 3.x terms. In any case Advantage/Disadvantage is a different mechanic from flanking/CA in 4e, though again you can draw SOME parallel. I don't know about DDN Slayer, but the 4e Slayer was not super unique. Clearly if DDN slayer works almost exactly like the 4e Slayer then it is something of a '4e-ism' but my understanding is that fighter type character mechanics in DDN are QUITE different from those in 4e, nor are all of the 4e slayer mechanics either typical of 4e nor unique to it.
Backgrounds existed in previous editions too. In 1e they were called 'Secondary Skills' and defined your character's previous profession(s). In 2e there were Kits and some other things that at least partly served that purpose. 2e/3e/4e/DDN all have similar but different mechanics for character background. Again, it is hard to compare exactly, but in any case 4e's backgrounds were a fairly minor part of the system. DDN's seem much more significant.
Bloodied... OK, I give you that one. It seems like a mechanic that is emphasized and leveraged less in DDN, but that is the sort of thing that could change or that I just haven't looked at the right class/monster to see it in action.
Again, 4e isn't the first D&D to have 'at-will' 'powers'. 4e had them for ALL classes as a basic feature. They did however exist in a form similar to DDN as cantrips as early as UA in 1e. They definitely existed in 3.x. Again, I agree that you can interpret this various ways, and it isn't entirely ridiculous to see 4e influence. Certainly the DDN cantrips are more potent and useful in a fight than they were in previous editions. Again though, where is the integral power mechanics of 4e? Its not really the same sort of thing mechanically.
This brings us to the real nut of the problem. I see 4e's design as highly integral and holistic. The PRIMARY attribute of 4e design is globally consistent mechanics. I can understand how that's a hard thing to graft on and a big thing to consider accepting, but I think that it is possible to construct 4e-like class mechanics in a way that avoids the objections people had to 4e. I am not really impressed with WotC's design chops that they won't even give it a try when many of us can see real significant advantages to it. In a sense without this sort of design concept DDN can be NOTHING like 4e, inherently. Any one single minor '4e-ism' that happens to be grafted onto a game that is fundamentally almost nothing like 4e doesn't really answer the desire.