[3.13] Update retroactive comments from GH-117741 (segfault in `FutureIter_dealloc`) (GH-121638) (GH-121642)

Update retroactive comments from GH-117741 (segfault in `FutureIter_dealloc`) (GH-121638)

Address comments
(cherry picked from commit 65fededf9cc1780d5edbef8a6e0a7cf9bc15aea6)

Co-authored-by: Savannah Ostrowski <savannahostrowski@gmail.com>