It's a good question. I'd be surprised if Betts has told the Red Sox to not even bother making any extension offers.
As you have often said, players hire agents for a reason, and I doubt that Betts's agent would tell him to take the stance of not even considering an extension.
Regardless of Mookie's public comments on the matter, there is a risk factor in playing with no contract after this year, and his agent would surely not counsel him to completely disregard that risk.