It appears that the snooze function is straight from Google Inbox (inbox.google.com). Meanwhile, you still can't unmark messages marked as spam in Google Inbox.

It appears that the snooze function is straight from Google Inbox (inbox.google.com). Meanwhile, you still can't unmark messages marked as spam in Google Inbox. I kind of alternate between Gmail and Google Inbox because they present different views. It's all pretty confusing.