Thats a very far cry from the previous claims that she stuck her tongue out
There is a photo of Meghan Markle sticking her tongue out at the garden party, so it did occur. What is unclear is the context. I am not criticizing the action, just noting it did occur.
I don't think one can conclude that just because she found the garden party boring, there was an instant leap to wanting to leave the BRF. I think though, that if she continued to find public duties stultifying, that would explain why she described life in the royal family fishbowl as soul crushing (paraphrasing as I don't recall the exact wording).