this is not my experience, a local branch offer a statement that type of thing, but once you ask for a new passbook or account changes no way, I closed my accounts in Bangkok and opened them in my hometown when I stopped working .
I've not heard that. But its logical because can offer a higher level of security, however, the current sim verification although cumbersome seem adequate, they probably phase it in rather do doing a big bang.
just had a thought, for my visa extension I live with my wife, and have fill a Thai form also residence certificate, it requires the house owner. Details. And copy of the blue book and her ID
BTW I got a second sim on AIS, account, it was in my name and they needed my passport, I called them about my first aacount and asked them them is the second there and verified, its there but not verified, you need to go into AIS with your passport to do that, it might be worth a call when your back make sure its verified. The helpline is good