I haven't had dancers preempt the calls, but I as a (contra) dancer have
sometimes anticipated a square figure sequence. I see dancers who dance
with swing, scottish, English, or square "accents." Perhaps the challenge
is when the dancers are used to the habits of another form (eg dancing with a
contra accent) and have to quickly switch to another form (eg
squares).
I think we have to train dancers on our expectations for squares the same
way as our expectations for contras or other forms.
I like how some callers say just before the music starts that, in square
dancing, there is the figure that's taught, and then "there are