If Tony can still do it (or at least a voiceover) whenever they get around to an Episode X-XII trilogy, I would hope that it involves R2 and 3PO several decades or perhaps a century following this trilogy. If not, just R2.
I’m not too hyped for a “post sequel” trilogy. But if it has to be made, it should come out at least in the early 2030’s so that there’s some breathing room between trilogies. And yeah, it should take place firmly in whatever the Disney canon’s Legacy era will be.