From www.dictionary.com:

con·gre·gate
tr. & intr.v. con·gre·gat·ed, con·gre·gat·ing, con·gre·gates

To bring or come together in a group, crowd, or assembly. See Synonyms at gather.

I think it could be argued that standing in line to use the facilities does not constitute "congregating" at all.

In any case, how about this: I'm in J on a 762. The cabin only has a single lav. I get up to use it, and it's occupied... No problem, I can wait. It's occupied for a long time... I really gotta go... Finally a FA comes out! Wouldn't it be more appropriate for the FA to use one of the coach lavs, considering there are so many more of them, than the one biz lav, especially since we're not allowed to go to either the coach or F lav?

Anyway, I just thought I'd add some fuel to the fire.