well its not too difficult to figure out - you just need to do the math for it
hss typically has 20 rotators in "high season" and rush has approx 10. for hss there are 8 spots and they interview approx 50-60, so theres NO WAY they come close to interviewing all their rotators
for rush, theres 5 spots - so again, if you guess they have about 40+ rotators throughout the year, youre again looking at the fact that not all rotators will get an interview
thats just my thoughts
and for places like hss and harvard (i think?) - if they dont screen your application before you rotate, then you have to look at your own numbers and see if they add up to their incoming class usually. places like wash u and rush do pre screen ive heard (i.e. ask potential rotators what their boards are, resume, transcript, etc). so - if you rotate at a place that prescreens, your chances for an interview are obviously higher. otherwise they wouldnt waste everyone time and let you rotate for a month....arguably anyway
but if you rotate at hss or harvard and your scores are too low otherwise, good chance you wont get an interview.
my two cents anyway