It looks like MN have not only deleted the thread it looks like they have banned SSAUK too. I tried to message the account from my account and was told it was unavailable. I asked why and was told:
Thanks for getting in touch.
If you wish to contact Safe Schools Alliance, you can find contact details on their website: safeschoolsallianceuk.net/.
We don't allow advertising and promotion on Mumsnet, so it's best to contact them off the boards.
Best wishes
Lily MNHQ
MN have not been in touch with SSAUK by email to discuss the deletion or the ban.
Why does MN want to stop their members accessing content that would help them ensure the safety, privacy and dignity of children.