...but they still get transported to a "harmless demiplane" first though?
The old wording separated the spell into two different effects - banishing to the demiplane, or banishing to native plane, depending on whether the creature was native or not to the plane you're on.
The new version seems to be replacing the "returns to the original space" effect specifically, but it's moot either way. The creature is incapacitated for the duration, so all you need to do is hold concentration for one minute and they've got to find their own way back to your location.
I mean, if a spellcaster banishes a Fey creature from the Feywild... they shouldn't be too surprised that it eventually comes right back into the Feywild?
Yes, but that's not the problem - the problem is the "random location" is no longer optional and the DM RAW is only mentioned as choosing the plane. It is, essentially, a randomized Teleport that can target hostiles when in the Feywild, despite all those targets being native to the plane you're on. Given the size of these planes, the odds of the random location being anywhere within reach of the party are negligible, so it's effectively a removal from the combat and likely the session (possibly even the campaign) that would require a DM to create a method to return the target to within range of the party through the plane in question.
That's not the kind of overhead concentrating on a 4th level spell for one minute should create for a DM, and it really feels like this was a case of clarifying what types are extraplanar to the Prime Material without realizing the implications of the rewording when the description is shortened to exclude the "If the creature is not native to the plane you're on" clause.
I'm not trying to rag on this for no reason. I like the creature type changes, but creature types in general are only as meaningful as the things that interact with them. Since a lot of the stuff that interacts with them is sloppy, the type changes as a whole don't have a cohesive system to fit into. I know it's never been cohesive, really, but with Banishment in particular I also know this isn't something that they couldn't do, since Dispel Evil and Good still works in a perfectly reasonable way (though it only specifies planes for Fey and Undead, it won't randomly teleport them on their own home plane like Banishment does). That inconsistency is part of what I'm getting at with "sloppy."