I don't think that a subreddit that bans links to Wikipedia can be considered a good source of information.
I don't believe it does as I recently posted a comment with a wikipedia link. It does, however require more authoritative sources than wikipedia, mine did at least have several other corroborating sources. Perhaps the auto-mod is set to remove comments without at least one non-wiki link.
They encourage people who would otherwise have linked just to wikipedia to hunt out the sources that claim comes from and use those instead.
I hope they put in a note in their comment or said thanks at least, I'd hope for more there.
They were nice about things; the PM read "AskHistorians doesn't allow Wikipedia, but .... I clarified in my OP .... Thanks for prompting the clarification!"
To post an answer on /r/AskHistorians you have to have a degree in the field in question or proven experience in the field.
I don't think that people who consider Wikipedia the end-all-be-all knowledgebase should be considered for anything.
I was not posting an answer. I was correcting an error in an answer, and I thought that showing that it contradicted Wikipedia was productive. (The automated implementation of the subreddit rules disagreed.) I thought it would be great if my comment resulted in either the answer or the Wikipedia article being edited so that they were in line; this objective was vaguely achieved.
It is at least currently in the subreddit rules page, as linked to on the main site.
"Wikipedia, or any other single tertiary resource, used by itself not a suitable basis for a comment in this subreddit."
https://www.reddit.com/r/AskHistorians/wiki/rules
In general on reddit, if you've had a comment removed and think it's not right then message the moderators.