If you want to move to another team at Google, it's really up to that team if they want you. As long as they have budget for you, and they want you working with them, then you're free to move.
The problem with new hires is that no other team has any idea whether you're any good, so it take a bit of tenure to prove yourself and make yourself known to others.
I'm quite sure Guido would be doing whatever he wanted at Google
The discussion I'm referring to represented ending up somewhere that you don't want to be as a bit of a trap.
E.g. if Guido ends up writing shell scripts, but his real skill-set/passion is for databases. It's quite possible for him to under-perform, and then that performance used as a reason for the 'database team' to not take him.
The problem with new hires is that no other team has any idea whether you're any good, so it take a bit of tenure to prove yourself and make yourself known to others.
I'm quite sure Guido would be doing whatever he wanted at Google