I doubt it's being paid promoted, but I don't think your cynicism is unreasonable. It is pretty obvious that the big tech companies maintain a presence on this board and attempt influence through human and automated measures.
(I feel like I'm living through a bad acid trip)
Seriously though, speaking as a contributor to Nim, I can confidently say no-one in the Nim community organizes massive multi-post promotion campaigns like this. The only submissions that come from the core developers are the announcements for new language versions, and (unfortunately) none of the community members seem particularly inclined to regularly submit links to libraries/blog posts either.
I'm sure Elm developers do the same thing - it's the only way for such projects to actually gain recognition among other communities.
Is Mozilla a "huge company"?