It's too early to tell.
There are pros and cons to both scenarios, and i think i will have a slightly clearer picture when some front office dust settles. If the Sox bring in some farm-building type, he is probably gone. But until we know who is running the team.
The Sox do still have a strong lineup core in Bogaerts, Devers, Martinez, and Benintendi, and are not likely to find taked for Price, Sale and Eovaldi. They might keep Betts, hope 2020 works out better, and then re-sign him. But it also depends on what one year of an MVP is worth to other teams, as well..