I have 3 times seen a high flare manoeuvre and A/T 'kick in' - it can, Denti. It can be hilarious to watch. I watched a fleet manager try to perform a low fly-by. Try it in the sim sometime.
Yup, if you flare way too high that can happen. If any autothrust mode other than GA is or becomes active when below approximately 27' RA (indicated) it will go into RETARD, as was discovered by the THY crew amongst many others.
We never had any issue with it to be honest and no tailstrike due to it, in fact the tail strike risk on the 737 fleet is much lower than on the airbus fleet and highest during take-off using incorrect rotation rates.