Tangerine, how do you feel about a restricted suggestion, not for mature content, but for content that might traumatize people? Jack's criticism just isn't applicable to that case.
Similarly, I don't think Memory Alpha is all that comparable a situation (Beta might be? I'm not sure as to how, uh, controversial the things on Beta can get). Wookiepedia notably does not have content warnings, but they've had some drama related to their editorial decisions on a similar front.
Wikipedia's refusal to use content tags can be found documented here (and in the relevant talk page). The tldr is that they insist that content tags violate NPOV, are censorship, take up editors time, take up space, open them up to lawsuits if some pages lack content tags, and the disclaimer stating that wikipedia isn't always sfw makes them redundant.
Obviously these are all either nonsense or not clearly applicable to our wiki. We have no reason to uphold NPOV in this manner based on a strict reading of T:NPOV, but even if we did, it's not clear that what they're saying is correct. It's just trivially not censorship. Editors are volunteers, so they can decide what they thing is most important. Taking up space is true, but, uh, that's sort of the point, so I don't see the criticism. They're clearly not redundant, and we're far more likely to get sued by having none of these than some of them. Since we can hit the really obvious pages and stop people from being traumatized, when they obviously might not read T:NOT SFW before browsing. (Not that I think this is at all likely, just, you know, 1 epsilon vs 10 epsilon.)
Lyricswiki lacks content warnings but is being shut off soon due to the content therein. Harry Potter wiki has spoiler tags, but not outright content warnings. Most of the stuff around our size seems more sfw than us tbh. Though, I'm sure they'd say that about us if they didn't know about our weird niche areas.