So my GM got banned, but I had a 2nd account as officer in the guild. I created a new account (#3) to join the guild. The account was less then 24 hours old and only withdrew 15k and was banned within a few hours. It was on a different ip but I had had an account banned 2 weeks prior on that ip. Now why would they ban a new account for WITHDRAWING 15k when my botting account is depositing gold and remains unbanned? I am not using any pr0xys and it is a paid account. I did absolutely nothing else besides withdraw 15k, didn't trade it or buy anything with it.
Your GM was banned, so you are tagged by Blizzard. Any suspicious behaviour will then result in a ban. Taking 15k from the bank with an account that's just a few hours old, IS suspicious behaviour.
Ye, its always worth to appeal it. Anything major, done with fresh accounts is suspicious to Blizz, and lead to autoban or at least flagging, to my experience. So gogo appeal and claim you did nothing around the rules ofc and see what will happen, good luck!