You said you needed "...more feats and subclasses to flesh out the most common archetypes." I assumed that was your point since that's what you actually said. And if we're talking about the most common archetypes, then 5e does that already. From your other statements, it seems that what you actually meant was that you wanted more feats and subclasses to fill your niche and/or highly specialized concepts. You can hardly blame me (or others) for missing the point when your point was something different than what you actually wrote.
It's a matter of perspective. What you call niche/highly specialized concepts, I call common archetypes. What you call a suitable ways of making them, I call incomplete solutions.
If I really think about it, what I'm really missing in 5e are a generic skill monkey class and a generic magic-user subclass. The fighter for exemple has two generic subclasses: the champion and the battlemaster. I can use those for any character concept that knows how to fight. Now if you take the rogue, it's a different story. The rogue has sneak attack as a class feature. That gives him a dirty fighter/assassin feel that you can't avoid. The wizard's problem is that you have to play a specialist.
Addressing your actual point, my suggestion would be to not hold your breath. 5e is not going to be like 3e with a ton of specialized feats and classes. It's not designed to be so. I for one would not want to see the feat/class bloat that plagued 3.x in 5e. And I have a suspicion that WoTC isn't going to take a business model where they put out all that material either. Splatbooks and fluff for small pockets of gamers isn't something I see them putting out any more. What I do see?
An Adventure Path that includes another variant of sorcerer, possibly a psionist, and additional specialties for clerics. And that's about it.
Did you get this information in an official announcement or are you making this up?
And I'm not asking for bloat. I'm asking for a rogue that isn't a dirty fighter and a magic-user that isn't a specialist. You know, generic building blocks that you can use to make pretty much any character you can imagine. I didn't like the 3e/4e option bloat any more than you did. I don't think a sneak attack variant or a generalist wizard subclass are too much to ask.