That’s useful to see as context, thanks!
Allowing lambda(x,y): ... may conflict with ideas which are being batted around for allowing the use of lambda(…) for a more expressive Callable syntax. See PEP 677 with an easier-to-parse and more expressive syntax
It’s not a deal-breaker, just something to be aware of.
I prefer this as well. The tuple[object, object] example was, I think, for parity between (b, c) and b_c in context.
Requiring type homogeneity is already somewhat messy with *args and **kwargs.