Thanks NotTerfNorCis - so not forced out by TRAs at all. Friends Meeting House was uncomfortable hosting an event
So what happened was this:
As you said, the venue isn't on the tickets because WPUK knew it would be bombarded by all kinds of objections and threats (including potentially bomb threats).
Nonetheless, TRAs tracked down the venue and flooded the staff there with objections, and, knowing TRAs, egregious lies.
As a result the venue caved.
WPUK offered to attend a mediation session but because the TRA objectors would not attend, no mediation could take place and the venue was lost.
It's pretty black and white, daimbars.