While the sorcerer subclass isn't an issue the way the wizard one was, it's really its own thing, not a wilder.
By default, your spells use components. Your ability to not use components is limited by that psionic die. The rest of the time, you are casting spells with magic words, mystical gestures, and animal droppings just like everyone else.
How does that sound like a wilder? I don't think we necessarily need a wilder in 5e, but if we did, this wouldn't be it.
The other question I have is where would that subclass fit into Dark Sun? They say the majority of sorcerers on Athas have that subclass. But they don't tell us what they are doing with sorcerers (the 5e class) on Athas to begin with. Traditionally, you've got your mages who defile or preserve, and "sorcerer-kings" are powerful defiling mages. I'm not sure how that even intersects with the 5e concept of a sorcerer and this subclass.
Maybe it's just their way of saying "hey, a subclass that gives you some psionic ability is a good way to represent that every elite character traditionally has some psionic ability in Dark Sun--so here's one of those subclasses for sorcerer", but it is rather unclear.
At least this one doesn't preclude an actual psion class, and nothing it has really steals from what an actual psion class would need, so there is room for one. I think that's the concession they are giving to those of us who want one, but I don't know whether or not we will get one.
If we do get an actual psion class, then I'd be okay with these also, but they really want me to provide my feedback on this without knowing if there will be an actual psion class. Sigh
I was going to say I wonder what their motivation is one being so bound and determined to give us some psionic stuff even without a psion class. Do they feel they need to see how stuff that isn't a full class can fit with the game first before they try the class again? Do they have a product they are trying to get done that just really needs some sort of psychic warrior? But then I realized it might just be a matter of where the creative juices are flowing at the moment and not a matter of any commitment to anything in particular. But then I see that it's got Jeremy Crawford's name on it, which almost always means it's something they're are seriously working on--usually for release soon--and there are four other people on it.
So this is something they seriously are planning on putting out, and it absolutely is not (at this point) coming with a full psion class. What are they doing that they need psionics so much for right now that they can't wait for a full psion class? I really hope it isn't Dark Sun (because a Dark Sun book without a psion would be bad), but unfortunately that's probably what it is.