I could be wrong but I think I vaguely heard someone on ESPN mention that the Browns actually have some insurance on if Watson were to miss significant time and if that's true, they could get back a good amount of the cap space, but probably not until 2026 and 2027. But by then it could still be a huge sum of money added to their reported cap space each of those years.
It has to do with the nature of the injury, where it occurred and if the Browns were aware of all the treatment/rehab stuff going on. It's a bit complex.
Either way, he's done in Cleveland. That was a disaster, and the fans HATE him already. In fact some cheered when he got hurt on the field when he did. I don't think CLE fans are feeling bad about the news.