Where is the 1 out of 15000 number coming from anyway? Someone mentioned a mistake and someone mentioned 15K and we jumped to the 1 in 15K conclusion?

So I clicked 20 random ways. 2 were natural ponds. 2 were river areas. 2 were gone/dry ground. 2 were swimming pools. 1 was industrial emergency water pool. 1 was waste water plant basin. So that's (unexpectedly) 50% wrong in this arbitrary tiny sample. Sure, it's not technically a wrong change based on swapping deprecated tags. But at the same time, who knows when the feature was added - possibly before a tagging scheme for such features existed.

Personally, I think this should really be a MapComplete task instead and each case manually reviewed.