Unless you changed the ending to where his Force Ghost is Ewan McGregor standing next to Hayden Christensen, it doesn’t make sense.
I hope that never happens in Return of the Jedi. It is bad enough with the nonsensical decision to have Hayden in there from 2004.
I’d prefer to hear Alec Guinness’ voice as Kenobi too. But for years it seems Lucasfilm have often chosen the “quicker, easier more seductive” route. So Ewan’s voice it will be, even in content after the OT.