I don't see how moving Bellinger as a salary dump makes any sense given that this is a mediocre offense as is. I found it dubious they'll be able to trade him for whoever and still add an equal or better players for any time of particularly notable cash savings. So let's say you trade Bellinger for Castillo
Bellinger makes 27.5M this year, Castillo makes 22.75. So, for 2025, you come out 4.75M ahead, but then you need to replace Bellinger's bat. Pete Alonso is going to set you back probably 20-25M annually, so will Santander and neither of them bring anything defensively nor the positional versatility.