Will we make type-hint only deprecations a pattern now? FWIW, it seems nice it seems like a nice way to potentially get some feedback about impact (and I guess some libraries may clean it up before there even is a warning, which is a small bonus too)!

I do have a slight worry with this one that while it won't be much code that is affected, it may not always be obvious how to replace resize. Typically, one can concate, sometimes use fromiter occasionally it may just be a reshape anyway.

The least obvious extreme case might be that the resize actually does make sense and one might have to use data = bytearray(...); tmp_view = np.frombuffer(data) (to actually keep reallocating).

Internally, we seem to use it mostly in places where we're reading from a file, and the array should be extended. I think this would often involve a copy (not sure how likely it is memory right after an array allocated earlier is still available). In any python code at least, this is fairly trivially done with concatenate.