getting new phone

Apple does not provide this type of information in advance.

The Phone 11 Pro was discontinued in Oct 2020, so a guess would be that updates will be available for another 4-5 years. No guarantee on that though.

For what it's worth, Apple is still providing updates for the iPhone 6 Plus, which was discontinued in Sept 2016.

I doubt that you will find a "new" 11 Pro. If you do, it has been sitting in a warehouse for 2+ years.

No one here can answer that. Apple has not made any statements as to how long it will be supported.

It probably has a few years of support left in it. That model was discontinued in September of 2020.

I believe the general "rule of thumb" is that you should be able to get updates for six years after original release.

That being said - I guess you have to decide whether to pay less for an old model more often, or just buy a new model once every six years. I bought my XS in 2020 when the model was 2 years old. I don't plan on buying a newer phone unless I have to.