You know, I really just want them to make a Space Ranger class. I mean, how long do I have to wait for that? And I don't mean fluffing an existing class to mimic what my ideal of a Space Ranger would be. Oh no. I want full on new mechanics. I want a button on the back of my character's pack that lets him do karate chop action. I want a laser beam coming out of his hand, and I want a bonus action retractible face mask that gives him the ability to breath in space, and I want that to be a class mechanic, not just some "suit" that he can buy. And the mechanics better be very, very different from what's already out there, because I envision a Space Ranger being very, very different from everything that's already been done. You might say that all of what a Space Ranger is could be accomplished by providing a space suit for a specific amount of gold and picking any class to go with it, but that just won't fit my vision of this game.
Look, I love psionics in these games, I always have. But the fact is that the Psion was a Wizard that had a permanent Subtle Spell on all spells, they used Spell Points rather than slots, and they had a crystal instead of a spell book. Switch out the spell list, and there you literally go. The Psychic Warrior was, literally, a Fighter with a 1/3rd progression of spell points. The Soulknife couldn't do anything except hit things with his fancy blade. I just looked it up, all of the Soulknife's abilities were tied to making his blade stronger and better. It was a literal One Trick Pony.
Now, I think the uniqueness of the Psion can justify its own class. I really do. There were different kinds, from the teleporter, to the shape shifter, to the mind control master. They could get their own subclasses and everything to make them great. This new UA makes me think they got rid of the Archivist from the Artificer because they wanted to utilize something similar for the Psion, they're just not ready to reveal the whole class, yet.
All that said, I've got mixed feelings on this execution. The Psychic Warrior is basically a Jedi. Some Force Push abilities and a weak telekinesis. Ok. I can see how that could work. But having access to Psionic Spells was kind of the Psychic Warrior's thing. I can see them putting in a 1/3rd progression for Psionic Spellcasting, even with what they have now, and it wouldn't hurt anything.
The Soulknife is fine as a Rogue. They work as Monks, I guess, but Monks don't use weapons, unless you really, really want to make a Jedi. And I think the point was that the Rogue can get his Sneak Attack with his Soul Blade.
As for having a Wizard subclass, I really don't think it was necessary. Psionics isn't magic, so if a Wizard wanted to study psionics, they'd have to basically multiclass. That's where the Cerebromancer prestige class came in. I suppose you could call it a Cerebromancer, and have it be a Wizard who divided his time between magic and Psionics. But meh. Psionics is its own thing, in world. Let it be its own thing. I don't mind using all the same mechanics, because lets be honest, there's no reason to break something that's working, but let it be its own thing.