So you would argue for not innovating/doing anything new if its not something that was in the campaign since season 1 when the core books came out? Seems like things would get stale pretty fast.
Not at all. But IMHO new things like that -- which lets be honest, are being added only because it suits the marketing needs of the new books -- should be added in for flavor, and not as an underlying core element of an entire campaign setting, which Madness (or certainly "trapped in another demiplane") most certainly is.
Madness was a good example of something that shouldn't have been added, honestly. The entire point of a Madness-based campaign, like Call of Cthulhu, etc., is that underlying sense of dread, unknowingness, and ultimate insignificance that permeates the characters existence. That wasn't the flavor of the AL Moonsea campaign to begin with, and as a result, when Madness got shoehorned into Season 3, it felt awkward and ham-fisted. The 'traditional D&D' of the Forgotten Realms is for the most part wayyyy apart from anything like that. Trying to introduce a feeling of lost sanity and the ultimate insignificance of a character actions on the universe at large is kinda muted when your second-level character helped kill a young dragon and now wears its skin as a cloak, and the week before that gleefully killed a bunch of undead musk ox. The characters in FR/AL/most fantasy campaigns are supposed to be the glorious, strong, unbowed heroes, and Madness -- as a campaign structure -- doesn't work well with that.
I think the 'new' elements are a great idea, and are exactly the sort of thing that worked well with the Encounters -- each season, a new 'mini-campaign' with its own setting/location/storyline, and possible mechanics. That worked great, as far as that went. For example, I would have loved to have seen an Encounters-based version of this new Ravenloft Setting. I would love to see an Encounters-based version or Al-Qadim, or Spelljammer, or Greyhawk or Planescape, etc. Separate but parallel mini-campaigns alongside the main Expeditions storyline. But not
replacing the main Moonsea seasonal storyline of Expeditions.
Of course, with the removal of those terms, things don't fit as neatly in the whole structure as they would have otherwise. But as had been stated, the format of Season 4 was decided upon way before any of that restructuring, and was an unfortunate accident that they ended up being announced the same week.
AL appears to be designed as a campaign that resets twice yearly, while still allowing other players to continue playing their characters from previous campaigns.
Except that it's not. Had each Season been involved with a completely different theme, settings, storyline, etc., yes, I could agree with that. And we all have multiple characters at various levels, because there's only so many mods available each season at a particular tier. But since Day one, it's been the Moonsea. You have a common thread (Phlan, refugees, factions, etc.) that keep everything woven together. Encounters? Yeah, Encounters is definitely a flavor-of-the-month deal, and by runoff, bleeds into the Expeditions. But the main storyline in AL has still always been the Moonsea and the common thread has been Phlan and the refugees. But now the entirety of Season 4 concept is being uprooted and dropped into the Mists.
Personally, I would have loved to have seen something along the lines as had been done before. Season 4 deals with a different town in the Moonsea, or the like, and maybe, I dunno, the Mists are trying to reach out and pull the city into Ravenloft, and as a result, horrible gothic horror monstrosities are emerging or showing up or rampaging or what have you. The Players (including the everpresent refugees) have to try and keep the local region from being pulled in, etc., and then at the two-round finale of the Season, something horrible happens, and the players are actually transported to Barovia, and have to defeat some miniboss -- with a guest walkon appearance by Strahd himself in the background -- to stop the appropriation of the city or what have you, and then at the end of the mod they escape the mists and all is well.
But the key point would have been that it still would have been possible for that portability to remain, and allow the character to still play other mods, like a season 3 or season 2 they missed. Or they would not have to worry about missing an important mod in season 4, or risk a character permanently being locked out of playing anything else because they can't get the right table together to get him back out.
Trapped in the horrifying Mists themselves for a big two-round finale or Epic itself is cool, and fun, and great. Or trapped in the mists of a brand-new, completely self-contained mini-campaign is also cool, fun, and great. But trapped in the mists for an entire season out of an whole ongoing interconnected campaign? Not as much, in my opinion.
Regardless, I think I and others have expressed our grievances enough; what's done is done, and what will happen will happen, and we'll have to see how it all pans out in the end. As mentioned, I'm sure I still will play the Ravenloft mods if available, because I like the concept of modular gameplay that OP typically provides. But it will be with a specific throw-away character made just for it, and I will not be playing any other of my existing characters in anything in Season 4, that's for sure. I can't guarantee I can get them back out, or play when my local group wants to run a Season 2 mid-tier mod he may have missed, or the like. Season 4 will be on pause for us, and we'll look towards Season 5 to hopefully be able to play with our storyline-invested characters again.