S.. Congrats to YOU!.
Good job.
Sounds like things are in a good routine (minus the 3 am wake ups)... so I wouldn't mess with anything. It might just be a phase he is going through. Don't start getting up with him now. :)
Perhaps you could offer (at bedtime) to leave a nightlight on in the bathroom "in case he wakes up and needs to use the potty"... so he doesn't feel the need to come tell you about it... make it a "reward" for him... ("You do such a good job in the potty now that you don't even need me to be there, so would you like to put a nightlight in there for when you wake at night? Then you can just go right in there and use it, without having to hold it while waiting to tell me" -- or something along those lines).
But really, I would just wait it out. If he is not being "rewarded" (you getting up with him or him getting in bed with you) then he will stop eventually... Be glad he isn't just waking and wandering around the house without your knowledge!!! :))
HAng in there!