I've e-mailed a few people for clarification on this rule. Along with the reported "must sign by Tuesday" rule, which I've also asked about, something doesn't add up. According to these two rules, as they're being reported, we would have to cut someone to make room for Tank, who would revert to our reserve/suspended list in 24 hours, but we couldn't re-sign anyone to take his place after that because it would be after Tuesday. That doesn't make sense.
Over the past two years, we've signed lots of players after a Tuesday. We even signed Billy Cundiff on a Saturday, and he played the next day. Unless it's a new rule this season, the whole "Tuesday deadline" thing doesn't make sense.
Also, players who were suspended during the offseason don't have to be on the 53-man roster for a day at the start of the season before going on the reserve/suspended list. They can go on the list at the same time as the cutdown. So why would Tank have to be carried on our 53-man roster for 24 hours? Unless it's a rule specific to signing a free agent who already is suspended, it doesn't make sense, either.