In Julia, the (+) function is commonly overloaded

The [] is as well. For things that have no shared interface. (E.g.: Int64[1][1] contains two calls to the [] generic function, which have no interface in common.)

Plenty of definitions of (+) are not commutative. E.g.: for strings.

There is some package which uses the (+) generic function internally, meant to be used on numbers. You call it instead with some kind of symbolic expression type. And it just works. Yay! This is the kind of stuff Julia afficcionados preach.

Then suddenly the package gets updated so that it uses (+) in a way which assumes commutativity.

Your code breaks.

In your world, how would you be notified of a change that some internal use of the (+) function now assumes commutativity?

Or when Julia afficionados preach the amazingness of being able to just throw a differential operator or matrix or symbolic whatever in a place, are they just overselling something and should stop?