Admins are not exempt from criticism. Just because they are admins, doesn't mean they are always right, especially on something that is of speculation in nature. I'm also an admin in other wikias, and I always welcome anyone to voice their critics and suggestions to understand others' perspective.
A lot of things they undid were based on speculations, and they were supported with weak justifications.
Any editor is of course able to disagree with an admin's actions or contributions. However, admins are given wider latitude in reverting edits that are in contradiction to the wiki's manual of style and established policies. Furthermore, editors are not banned for disagreeing with admins in good faith -- they're banned for either obvious bad faith issues (posting blatantly false information, vandalism, etc.), or toxic behavior (repeatedly forcing a disputed version of an article instead of discussing such additions on the talk page and achieving consensus, personal attacks, etc.).
In this case, the wiki has for over a decade had the basic scope that it is not a spoiler-free zone. There is and will not be any modification of how material is presented aimed at hiding spoiler information from readers.
As for the name etymologies -- this is definitely a valid complaint on its face. However, G-SANtos is writing up an addition to the manual of style with sources illustrating that the authors of this franchise have regularly and consistently chosen character names on shared themes. Hopefully this will illustrate to readers why this wiki allows the speculation into what the names are intended to mean, along those themes.
Personally, as long as the etymology section clearly notes when it is presenting a proposed etymology versus an explicit one, I think we should be fairly safe. As with all policies, though, that's definitely up to whatever the current consensus is, and you are free to start a discussion on the matter. I'd ask both of you to please focus on the issues, however, not the parties involved, as the above discussion is closer to personal attacks than is preferred, instead of content criticisms.