For those who still can't seem to understand why Waitrose thinks that there were many NT families there, you've ignored missed one of her earlier posts. She explained that it was heaving. The majority of children with SN need a session to be considerably less busy than usual, for a variety of reasons. Including space - for wheelchairs or other equipment, and less sensory overload from noise.
So if all those families there had a child with SN, and it was middling-busy with other children with SN, the next ones who arrived wouldn't join in. They'd leave, disappointed, and go home, like Waitrose's family did. They wouldn't be able to join in, and get the splash park to the point of heaving.
Ergo, she assumed that may NT families were there.
But she didn't go in screaming and name-calling, like some people are making out. She just went home. Presumably telling her children that they'll have to wait until next month.
For something that NT children can access every bloody day.
Waitrose 
Sorry there are so many entitled, thoughtless people. Out there and on here.
And I hope your local council do something about it.