Do you include folks with level 3 non verbal autism with greater epilepsy frequency and self harm in the group that doesn’t need a therapy?

You have to look at other body language components along with the lick. This is a lick is missing some stress signals that may mean it’s less anxiety driven or only partly anxious. A video would be more informative.

There is no whale eye here (whites of the eyes), eyebrows are ‘somewhat’ relaxed (not totally sleepy relaxed, but not ridgidly flexed either), ears are not flattened/down in an anxious position (see the linked article below for stressed vs relaxed face and note Clara’s whale eye, folded ears, and eyebrows in the stressed image).

Rigid eyebrows in a stressed expression: a great read on stressed vs relaxed face side by side pick of the same dog: https://eileenanddogs.com/blog/2013/02/14/dog-facial-expressions-stress/

Here’s a good example of stress vs relaxed lip licks: https://youtu.be/kMirei9-n18