Several things, IMO.
-Removes a long-disliked gamemode that people have been asking to be removed for years, which improves the chances of a more favorable gamemode being picked in the secret rotation. This is probably the biggest benefit.
-Removal or the possibility thereof could see people who are passionate about it moving to rework it. Ling has been stale for a long time, with only a few updates. Nobody has taken a full rework on as a project because there are more interesting or enjoyable projects to dedicate time to that benefit the server. The people who enjoy it have not worked on it; this may push a change in that. We saw this happen with skrell when The Fool Who Shall Not Be Named made a PR to remove them, and skrell have never been in a better place than they are now.
-Acts on the aforementioned server poll and years of requests of the community. Though, again, gathering an updated opinion beyond git and the forums would not be a bad idea. Things may have changed, though I personally doubt it.
IMO it is not a bad idea to remove a disliked/broken/stale piece of the server while it is being fixed, or while looking for someone to fix it. "Rework don't remove" is an annoying buzzphrase. Things get removed almost weekly from the server to improve it; this just happens to be a much larger scale.
While the core theme of ling (body horror, paranoia) is an excellent fit for the server and a personal favorite theme of mine, its execution of those themes are poor and stale. Part of it is bad antags, part of it is limiting mechanics. I don't believe anything would be lost by its removal. I think removing it for the time being, with the possibility of it being permanent, is a net gain for the server. I don't think anyone on either side of the argument would be opposed to seeing it come back in a totally reworked way, though, so if anyone is that passionate about the game mode, To anyone who is passionate about it, as I see many are, I suggest gathering the gripes people have with it as feedback, and trying to undertake the project.