Definitely do this. I tend to ignore the main page in favor of the discussion section because it's all meetup announcements.
Are you aware that unlike in the discussion section only a small fraction of the main section post ever get to the front page and you have to look at the Recent Posts bar (or the Recent Posts page, or Follow links in Recent Comments, or ...) to see the others?
All the meetup announcements get promoted, so the front page ends up full of 'em: half of it right now (5/10) is meetup announcements, and with the addition of the quote threads only 30% of the front page is currently 'content'. While meetup announcements are all well and good, it seems counterproductive to have them up there after the meetup date, as is the case with four out of the current five -- it just clutters up the front page even more without providing any benefit.
If post promotion is reversible, it would seem to be a simple step for one of the moderators to depromote each meetup announcement once it's taken place.
(Apologies if this is the wrong place to put an organizational suggestion; I didn't find any obvious better place.)