I realize this thread is actually more about a 'swing-draw' vs. a 'straight' bow arm, but to me, the concept of "push-pull" has much less to do with how you draw the bow, than what you're doing at release. (IMHO)
I liked Dennis Kamstra's "Tips From the Old Timer" in the Dec/Jan issue of TBM. Now, he focuses a lot on grip, and how it relates to this, but regardless of how you grip your bow, or what position your bow arm elbow is in, you can still "push" your bow hand at the target. I do shoot with a fairly rigid bow arm, simply because:
a.) That's one less variable for me to worry about as far as a consistent stance/draw.
and,
b.) That's what "feels" right for me.
I'm not trying to tell anyone how to shoot, but I find (for me!) that when I come to a good, solid, "full" draw, and focus on "pushing" (mentally at least!) my bow hand at the target, I'm much less likely to collapse.
Now, back to the original post's intent. Just for clarification, I do have a distinct pause before release. Sometimes I "swing" the bow up into position, and sometimes I start from an upright, straight arm position. But before the string slips away, I'm locked in on the target, "pushing" the bow and "pulling" my drawing arm elbow back.
Not trying to muddy the water, but while I'm still learning, I think push-pull can be applied to any style. Your thoughts?