I fully support this, for tuples as well.
I’m a big fan of duck typing. I don’t use any type-checking tools and would never want to get into the kinds of messes that I see others create with them; but I sometimes annotate my interfaces as documentation, and use collections.abc typenames to do so. If I write something that conceptually expects an immutable mapping of integers to whatever, I’d like to be able to accept a list - or a tuple - transparently. That kind of thing is a big part of why I use Python. Having a .get method would help support my style of programming.