The answer is a mostly yes. If you go online and obtain an update bypassing the psn firmware upgrade and don't have the lanch12345 folder on your ps3 BUT there's a possibility of being banned. The other way is there is a website (I wont link it but you can google it) that offers ps3 game updates.
Here lies the problem: You most check out the ps3 compatibility list and see if updates are compatible. I've read that some people have even taken their jailbreak online and played hd backups.
I think it's a horrible idea and the only reasons why I would backup a game is to extend the life of my laser, decrease loading time (modnation is horrendous) and try to create less heat (I have a backwards compatible 80gb, gets way hotter than the newest ps3 fat 80gb I had before).