TBH I'd expect that now NodeBB could be considered "notable enough". Especially since there is some forum software that seems to be smaller there:
Thredded has a page an an entry in the comparison article, despite it having less media coverage (looking at news section in google, there is nothing, when there a few articles that at least mention NodeBB), and less stars and forks on GitHub.
There is actually a note that the article may not meet notability guidelines on the thredded page, but apparently it has been there since 2016 and other than one deletion that was contested nothing happened to it. Ironically, one of the links by the person contesting it is to a NodeBB instance
I'd say the same about Syndie, though I can't be sure because I find a lot of articles about a lot of things, but not the forum software. And also - its last release was in 2016...
Beehive Forum has mostly dead links and 2 of 5 external references are just sites that were using Beehive. 3 others are about one vulnerability...
So, I think that unless editors personal feelings would affect their work or they want to wipe a few other pages about forum software (if that's the case, then sorry to these projects!), NodeBB is notable enough by Wikipedia standards by now.
There is even a book mentioning NodeBB now: Node.js Design Patterns (There are actually a few, but this one is relevant and gives some information about NodeBB - not just mentions it).
Though I think the problem of NodeBB and other forum software is that... There is very little news outlets might talk about. Unless there is some big vulnerability or something, it's just usually nothing newsworthy. So there is a lot of things like tutorials for NodeBB, but very little "news coverage".
Oh well, I might give writing a new Wikipedia article a shot, though I'm not very experienced with Wikipedia and I think I might have an oversourcing problem (that is, last time I edited a Wikipedia article I removed half of the sources I added before publishing the changes, because no one needs a source every sentence where one is more than sufficient...)