Many other aspects of the letter overstate the case, But go ahead, send it.
I know that others might wonder what the recommendation states:
The University should give careful and thorough consideration to the relative benefits and disbenefits of its relationship with Stonewall, bearing in mind the issues raised in this report. In particular, it should consider that this relationship appears to have given University members the impression that gender critical academics can legitimately be excluded from the institution XXXXXXXXXXXXXXXXXXXXXXXX); the potential effect of this on the University’s obligations to uphold freedom of expression; the effect on University members’ understanding of the values of the institution; and the effect on those members of the University who hold gender critical views. If the University considers it appropriate to continue its relationship with Stonewall, it should devise a strategy for countering the drawbacks and potential illegalities described above.
Given the respected legal authority behind that report, that reads like a helpful steer as to appropriate action.