If you were whistleblowing to the press you would undoubtably get the 'in the public interest' defence on this.
There is no way recording a training session aimed at schools and other public bodies WOULD NOT be in the public interest to know.
Its a matter of whether institutions are fully aware of who they are getting to train them and whether the standard of this is in line with their standards of safeguarding and equality.
If they are preaching sexist and homophobic nonsense or anything which is conflicts with their internal safeguarding training, then theres a problem.
This is why its important to get it transcribed and to get it on line and preferably published (which I'm sure the lurking journalists here won't be too adverse to).
They can report it all they like on twitter and get it taken down, the cat is out of the bag, and Barbara Streisand is thrilled by it all.
Its not as if any of this is a huge secret, seeing as they are actively trying to get this brainwashing program in front of as many people as possible.
Again, you CAN'T make the argument that its in breech of your privacy if you are actively trying to promote and publicise a particular idea / agenda even if its a closed meeting - if that closed meeting happens to be a public body.
You'd be laughed out of court by a judge for trying that on.