If Obi-Wan encounters R2-D2, I’m not sure which I’d prefer…
“Get out of my way, random droid! I don’t have time for random droid nonsense.”
or
“Wow, hello there, old friend. Good to see you again. But next time we see each other, let’s pretend we’ve never met.”
I think R2 will help Kenobi keep Leia safe, but it will be 11 years later he will see him again, and the droid doesn’t belong to him, it belongs to Senator Bail Organa.
R2 trusts Kenobi completely, so the droid will say anything to get to him.