It would not surprise me if Barnes was dealt this off-season. But I hardly consider moving him to be a fire sale.
The thing is, when GMs build, they appear to me to have "foundation players" and "supplementary players." (My terminology, probably not theirs.) Foundation players they build a team around, and they do so with supplementary players. As Devers is a controllable foundation, why move him just yet? Bogaerts? Probably a wait and see approach, but dealing him is probably unwise because of the pending shortstop FA market. Why would anyone unload the farm system in order to acquire a player for what will probably be slightly less than they can sign Trevor Story for a couple months later? His value won't really exist until after the "Shortstop Free Agent Bonanza" (also my terminology) of 2021-22 has settled and some teams are still looking for one. (And if not for the opt out, Bogaerts would also be a foundation player himself.)
I could see Bloom unloading a few players, notably Barnes and (obviously) Benintendi. But the other short term expendables like Eovaldi and Martinez are going to be too difficult to move anywhere, due to their lucrative deals. So if Bloom knows he is going to be stuck with these players, and because Henry clearly does not like rebuilding, I would not expect Bloom to unload all his talent for prospects as some ego-building venture.
I think a lot of this specualtion was that the team did basically nothing before 2020 in an atetmpt to reset the tax. But this was not a new thing either, as Henry had Cherington do basically nothing prior to 2012, an off-season where Ben was so hamstrung by the finances, he had to trade away Marco Scutaro just to accommodate career 4th outfielder Cody Ross. But that lasted all of one off-season, and BC had a spending spree before the 2013 off-season...