It looks as if my second guild bank, which I do not run as a leader, has been affected now.
I just checked today and saw empty tabs. Only me and another person are still active in this guild, he did not take anything out, the logs only show what I took out two months ago, which was a single item.
In my opinion this is a clear sign that the bug is still alive and not fixed. So you better be careful if you put something in.