But this is a playtest. Why are we wasting our time getting upset about filler mechanics?
I don't think it's filler, although I would hope so.
But your post made me think, why are wasting so much time getting upset about mechanics in general, instead of trying to see possible faults in the bigger picture?
For example, my long-time concerns about saving throws being mostly Dex/Con/Wis, with a little bit of Cha/Str and next to no Int at all, is not really so much about actual numbers, but rather the general concern that the game might have dump stats. Unbalanced numbers in spells & monsters ST might actually improve the overall result. I don't actually know because I've played too little to have statistics, but currently my gut feeling is that Intelligence is a dump stat in 5e.
Another problem with the bigger picture for me is character complexity (I'm not talking about scaling group complexity, that is fine, the core rules are very simple). I bought into the general 5e goal of scaling complexity using character choices, so that each player can dial on their PC's complexity, and also bought the specific idea of implementing it through subclasses. However, I don't think they are fully backing up the idea, they are
quite doing it, but not as much as they could. To follow the goal, I would expect them to lower the number of class features (which the player cannot choose) and increase the number of subclass features, for instance by moving the most complex class features to subclasses, and then simplify the remaining class features (and then of course also have subclasses with simple features). Instead I think we still have class features that are bothersome to keep track of, which means that after a few levels the game can become boring or annoying to a player who doesn't like to keep track of points, condition-based abilities, reactive abilities etc. and cannot be opted-out if they are class features instead of subclass features.
IOW the baseline complexity for managing your PC is still too high. Even if you play a "Basic" character with the low-complexity subclass chosen by default for you.