You won't come across as a drama queen if you say good-bye nicely...You told them you were leaving, so no one is scanning obituaries looking for you. I never heard of netequette, but if that is supposed to be good etiquette, I disagree with it.
I can't tell you how much I agree with you. This is a topic I would not normally comment on but I think it is simple courtesy to say hello (if you plan on participating in the community) or good-bye (if you've been a member of the community).
I used to wonder what happened to some of the Trip & T'Pol authors or heavy participants of the BBS at the House of Tucker and not just because they didn't finish a story. You get to know people and wonder if they're okay.