If they don't sign Bichette certainly Bohm is likely to stick around. If they do he's gone unless they trade Stott, and I don't think anyone wants that even if that's probably how it ends after 2027 (with Bichette/Miller/Turner the IF. Even if Trea isn't SS anymore I doubt he's going to the OF).
Don't think the Phillies can really afford to trade Walker before July. With Wheeler not likely to be ready on Opening Day and Painter a complete question mark he'll be used.
Either way, Walker and Nick are only getting traded if the Phillies make it worth the other team's while, and they can't really afford to be selling prospects. If you packaged Bohm and Walker together you might get $9 million in relief on Walker, but no players of any value in return.
Anaheim is in the top half of payroll already, and those other teams never spend money, not that you seriously thought they'd take on much of either contract.