I was just moved from Sprint to T-Mobile billing automatically. I have been using a T-Mobile SIm with a S-22 for months.
You might want to re-think being moved quickly.
In my account, I was removed from the administrator status and my line was set up as a "kids line". Of course a kids line is restricted.
My wife's line was now the administrator of the account but they did not know her name. I eventually got it all straightened out, but it sure was not moved correctly. I have not received a new bill yet, but it does look like the options/pricing might be correct. I am not positive on this, but hopefully the first invoice will be correct.