A large amount (20-60%) of the questions here are not code golf questions. It might also confuse new users.
Let's keep it as is
We've been Programming Puzzles & Code Golf, otherwise known as CodeGolf.SE, since our inception 5 years ago. Our name doesn't suit us perfectly, but it's part of our identity. And now that we're graduating, we should avoid changing our identity and embrace what we've accomplished as CodeGolf.SE.
That aside, the subdomain name "code golf," despite being only a subset of what we do here, is descriptive. "PPCG" is meaningless without context. Indeed, the rest of the Stack Exchange network knows us as Code Golf; few people know what "PPCG" is.
So let's stay us.
Let both coexist
When you go to codegolf.se, it keeps that URL (clicking around gets you to the same domain), but let the same be for ppcg.se.