I'd argue that this is a good policy, if you forget about it and there are sensitive documents etc contained within the mailbox then it's probably a good idea to erase it after a period of inactivity...
True, especially considering that a lot of accounts on Yahoo and AOL (basically part of Yahoo and does this same policy) are likely a decade or two old, so they may have passwords of like 6 characters and no 2FA, because that was super common back then.
Yup
I'd also argue that if there are emails on that account that are important.... And it's a temp email address for a specific event... Forward the important stuff to a more frequently used email account? Maybe?
Well obviously, but most users wouldn't do that, they don't understand security etc...