The retirement nonsense was all media driven.
That isn't true. Spinal contusions are extremely serious.
In most cases, it takes 6-12 months to heal and at least another 6 months of rehab. So to assume he will be able to play next season is very optimistic. Paralysis partial or full can occur. Most times its not permanent. There are a host of other potential issues including cardiac involvement In other words a spinal contusion isn't like a simple leg bruise. Hopefully, it isn't a bad contusion and Stafford would be ready for TC though IMO he might miss OTA's.
A lot depends upon the severity but to think he won't be susceptible to re-injury, especially on an accelerated recovery regime is optimistic at best. That is why IMO in a best case scenario Stafford doesn't play beyond 2024 and the Rams have a new QB. As I've said in other posts, the Rams would need to carry Stafford at least through 2023 simply because of the cap. If he retires or is traded or released in 2025 the dead cap is $12M which can be split over two years. It would also clear about $26.5M in cap to help pay for Mayfield's extension.
Snead would be remiss if he simply allowed Mayfield to walk. He's got to know his QB is one hit away from being on IR for a season. You can't build a team around that. Right now Baker Mayfield is a high tier two QB, with the talent to be a tier one player. The Rams can win with that. They need to carry Mayfield as QB insurance. If they tell Mayfield if he sticks around for 2 years he will be the starter in 2025 he will stay. Snead can tell Stafford he has a two year window to get another ring but in 2025 he needs to retire or be traded. Stafford probably would make more money in broadcasting than as a player.
Mayfield may never be an elite QB, though IMO he has the talent to be one. But the main thing is McVay likes him and that keeping Mayfield probably extends McVay's career with the Rams. McVay seems to feel that they can be a SB contender with Mayfield at QB, so that alone is worth the move in QBs in 2025.