> Hypothetically, if the language defined for i, x := range xs to have x repeatedly be a new reference to each of xs members, it seems like we'd avoid 2 gotchyas

I'm not convinced. I believe what you'd end up with is that someone will write a "Common Gotchas in Go" article about how, if you think you are operating on a copy in the loop, you are actually operating on a reference.

Really, it seems very non-obvious to me, why one would be a less surprising behavior than the other.

(The fact that the loop variables are not scoped to the loop body - i.e. closures will share the references - is another issue and that I would pretty unambiguously call a gotcha that should be fixed…)