To me, the only bad thig about trading Robert now is he'd be dealt when his value is relatively low. The return will be less than optimum and most likely wouldn't help the Sox in 2026. However, do we really think Robert will be on this team beyond 2026? I certainly don't. If he plays well in 2026, and he isn't traded at the deadline, he'll get paid by some other team for 2027 and after. If he struggles again, or is hurt again, he'll stick around all season and not be re-signed.
The best case scenario is the Sox hold onto him, he tears it up for the first half (and miraculously doesn't get hurt), and he gets traded for a nice return at the deadline. Do we really see that happening? History says it's unlikely.