The event seems to have been cancelled by the owners of the venue. Their sandpit and their say so as to who performs there.
That simply isn't the case when you are offering the public goods and services.
Blackpool BC was ordered to make a public apology and pay the claimant £25,000 in damages and a further £84,000 in costs in court for removing adverts for Franklin Graham's religious meetings from the sides of their buses.
Scottish charity the Robertson Trust, which had cancelled bookings by the Billy Graham Evangelical Association for hire of a conference venue, admitted this was unlawful, apologised and settled for £20,000.
Julie Bindel sued Nottingham City Council when a room in a library booked by a women's group was cancelled because she was appearing. Nottingham CC later accepted that this decision was unlawful and apologised and the case was settled for an undisclosed sum.
If Linehan, or anyone else under the Comedy Unleashed umbrella thinks their legal rights have been infringed then they can take action to enforce those rights or to be compensated for any loss.
Is this how you want the law to work? It only protects those with deep enough pockets to sue?
Being GC is not protected. You may wish it to be but as things stand it isn't.
It's protected as a belief just like 'Transwomen are women' is protected. I don't agree transwomen are women but I don't think you should be discriminated against if you want to rent a room and stand around saying it.
Really going hard on this religion thing, huh?
I believe in freedom of belief, yes, whether those are religious, philosophical, or metaphysical. And that people should be free to express beliefs that are legal, within the law. Sounds like you don't to be honest, or rather it should only apply to people you like.
However while the belief itself is protected manifestations that might be offensive are not.
In discrimination law it's not up to the individual to decide beforehand which beliefs are offensive though and of course you can't deny goods or services on the basis of what someone might say.