Linus Ullmark was involved in a bunch of trade rumours during the NHL trade deadline this year, reports suggested that Ullmark did indeed block a trade using his NTC, so the Bruins decided to keep the tandem together for the playoffs, but Swayman would appear in every game but one.
A lot of teams have been showing interest in Ullmark, and it seems he knows his time is coming to an end in Boston as well with this post he made on social media. It looks like Ullmark was saying goodbye to his teammates and the city of Boston.
It would be hard for the Bruins to build a contending team if they had $11-13 million locked up between both their goalies, and they wouldn't want to lose Ullmark for nothing in the off-season next year, trading him would be the best idea for the Bruins.