Do not forgot the second point of the slippery slope
(2) everyone agreed that documenting all operators this way is impractical or absurd.
While avoiding to inconvenience readers wanting to read all the manual is reason enough to restrict the manual scope, increasing the number of docstrings does not share the same problem, as docstrings are queried on demand, and do not inconvenience people that are not confused by the added docstring.
Again, you ignore the previous argument that and and or are the names of such operations (or at least, how someone who does not know the symbols may reasonably expect them to be named), they are not searched only “because Python has it”. I have never, for example, thought of suggesting we add an entry for ++ about string concatenation because Haskell use this operator. However, concatenation maybe would be useful (while I think it is not worth the effort).