I'm not saying Roblox won't try, but this project strikes me as very obviously legal.
If legality was a spectrum, I'd rank this higher than VLC Media Player (patents) and way above an NES emulator. I suppose it'd be below Android, and Oracle did sue over Android.
(Disclaimer, I am not a lawyer, etc.)
(also not a lawyer)
I'm pretty sure all the hand wringing about A.I. is going to fade into the past in the same way as every other strand of technophobia has before.
It looks like you see writing & editing as a menial task that we just do for it's extrinsic value, whereas these people who complain about quality see it as art we make for it's intrinsic value.
Where I think a lot of this "technophobia" actually comes from though are people who do/did this for a living and are not happy about their profession being obsolesced, and so try to justify their continued employment. And no, "there were new jobs after the cotton gin" will not comfort them, because that doesn't tell them what their next profession will be and presumes that the early industrial revolution was all peachy (it wasn't).