To reiterate my position from those other comments:
I disagree with deleting those synonym suggestion answers, and would disagree strongly if not for the fact they are still around and visible by at least some people. They provide documentation, and are helpful for people considering making other suggestions (demonstrating the format of pointing out number of questions, Wiki descriptions, and other factors) as well as details of tags under discussion. Tags have history but that shows only edits; not any discussion or rationale of why beyond a brief edit statement. Some suggestions have no real discussion or even detailed proposal logic, so not much would be lost. Others have a lot more to them.
I'm not a fan of the restrictions on the ability to view deleted posts (though I understand the moderation logic of not having everyone be able to see them), since in cases like this the people who would most need to see it can't (ie bringing a suggestion or its reversal up again). In fact, without that high rep level (10k) or being the original asker, nobody can see it - including if you commented or answered it, which really irks me sometimes. But that's a whole other topic. Suffice to say I think the discussion/rationale aspect of synonym suggestions is beneficial for all, and oppose deletion for anything with such value (again, not all of them have that). If each suggestion is its own question this becomes moot unless you also propose deleting those questions as they are addressed.
I understand the desire to get that question back on track in terms of who can suggest rather than suggestions. But is that something we at GIS.SE can control independently of the main SE system? If scoring is tied and we can't alter it, the question would belong only on SE Meta and cleanup wouldn't really serve much of a purpose. Otherwise I wouldn't be overly opposed to pulling out unaddressed suggestions to new questions, though I don't know how beneficial being retroactive in this case would be. Seems easier to just shut it down and make the change moving forward.
To summarize: I wouldn't delete any answers there to clean it up. I'd go ahead and accept your latest answer, then close the question so no new answers can be added. At that point, all new suggestions can be new questions, and your accepted answer will direct people both to post them as such and visit the relevant SE Meta questions to vote on changing how the system itself works.