If Whitlock, Eovaldi and especially Wacha and Hill come back to provide the same consistency that put the Sox ahead of the wild card contenders, then there is no reason to sell. They were good enough without Sale and Paxton all year.
But Bloom would then have to buy, because there are holes that can be upgraded to give the club a better chance to make the postseason and even advance, like last year. Adding an actual big league outfielder and first baseman, and swinging a blockbuster for a Luis Castillo are all within reach, if the Sox really wanted them.
The issue is that too many Red Sox free agents are not going to be re-signed, and Bloom can't just let them all walk without fetching a farmhand or two.