dieterdreist:
it can prevent people in the future from creating tags that may be ambigous or confusing
That seems unlikely to me. To see those “possible synonyms” you need to be on the “correct” tag’s page anyway. So, if you are, why would you then create a different tag for the same thing? (and if you did, would a red box at the bottom of the page really stop you?)
the case at hand was a leisure=swimming_pool and the possible synonym was amenity=pool.
If I were about to invent amenity=pool (for whatever purpose or kind of pool, not necessarily a swimming pool), I would search the wiki and when there is a possibile synonym I would find it and be discouraged, when it is deleted I would not find it.
