If you're asking about the the proposed new language about FutureWarnings, it seems fine to me. If you're asking about the PEP as a whole, it seems fine but I don't think it will make much difference in our case. IPython has been showing deprecation warnings in __main__ for a few years now, and it's nice enough. Getting warnings for scripts seems nice too. But we aren't rolling back changes because they broke someone's one off script – I'm sure it happens but we don't tend to hear about it. We're responding to things like major downstream dependencies that nonetheless totally missed all the warnings.
The part that might help there is evangelising popular test runners like pytest to change their defaults. To me that's the most interesting change to come out of this. But it's hard to predict in advance how effective it will be.
tl;dr: I don't think PEP 565 solves all my problems, but I don't have any objections to what it does to.
-n