Why Area51 doesn't have a twitter account (I couldn't find it) to tweet proposals?
like @StackUnix, @ServerFault, @StackSuper_User and probably others.
We discussed the idea of an Area 51 feed, but we decided against it.
Area 51 isn't an expert-followed Q&A site like those you cited. Area 51 doesn't really have a core community of "proposal followers" — and if there is one, I'm not sure we want to necessarily encourage that avocation.
Proposals are supposed to be created and supported by groups involved in that field. We don't necessarily want proposals to be pushed through by a group of avid Area 51 watchers, for lack of a better word.