Unfortunately, we do not allow solicitation of users to follow proposals in meta support nor in the posts and comments on the main Q&A sites. With so many proposals vying for attention, allowing each one to start soliciting support on the main sites became unworkable pretty fast. Such activity would be 'flagged' and removed.
I can appreciate the need to find a community for your proposal, but when you submit a proposal for a site, it is stated that you need to have access to an avid community to build it. You were asked to provide a description and links to the site or organization which was (presumably) heading up this effort.
Some of our larger ("graduated") communities have a meta post tagged
community-ads which may or may not welcome ads for proposals — do your research first — but the audience for those ads is small, and we cannot allow proposals to linger along with only a small accretion of users over time without a larger base of support.
It takes a lot of people to organize a successful proposal.
Promotion should be done predominantly outside of the Stack Exchange Network.