Apples warranty is basically international with exception of Sim enabled products.
They may decline to warrant it if it’s from a different region if it’s a compatibility issue. Basically it is to their discretion.

I had phones from Australia and Uk which was accepted for warranty locally.

The region locked warranty is only particularly important for countries with more than standard year warranty. It doesn’t really matter to us. Buying a phone that can’t accept local Telco bands is up to each individuals due diligence. Just a simple search will suffice.