I heard Creation Kit 2 is being updated and there was mention of UE5 being involved

[Z0mBieP00Nani]

Could CK 2 be used for the Oblivion Remaster in that case, or is that only going to be good for Starfield?

[Spirit_Shard]

Do you have a link to the source? Starfield runs on Creation Engine, not Unreal Engine. Oblivion Remastered runs on Gamebryo (before it was officially The Creation Engine) and Unreal Engine through a translation layer.