That pretty much describes my sittuation
Just tested. Leaved general chat, joined back and seems ok to me atleast (93 people in channel). Tried this with monk channel and no problems. I´m in EU by the way.
Maybe your previous channels are just full? Try to join different channels to see if problem occurs in them too.
Joined them all,1-2 people on each,I am from EU also and I know it is a problem from me because I asked my friends and neither of them got this problem,and I have it since before the patch,but I tough "everyone is on PTR,everyone waits for the patch so no peeps here" but it seems that it is a problem from me...