To my (totally uninformed) eyes it looks like maybe this could count as a SLAPP suit [1], in which case there's a possbility for a counterclaim for legal costs. However, Massachusetts apparently has "much weaker anti-SLAPP laws" [2] (than California, in the context of the article)

[1] https://en.wikipedia.org/wiki/Strategic_lawsuit_against_publ...

[2] https://www.vox.com/future-perfect/23841742/francesca-gino-d...