I think there was also another longer discussion, but I couldn’t find it. Generally this is a bad idea because subscript syntax contains implicit parentheses for brevity, so T[A, B] is equivalent to T[(A, B)][1].
Technically parantheses aren’t a required part of any tuple, they’re only there to resolves ambiguities, what makes a tuple a tuple is , the only exception to that rule is the empty tuple syntax sugar ()↩︎