This really doesn't make sense. Here are current MicroSort results from the Web site.
YSORT®
YSORT® to increase the probability of
conceiving a boy has resulted in an average of 73% Y-bearing (male)
sperm in the enriched specimen and 81% of the babies have been male.
(172/211)
If O induction favored girls, you would expect to see the boy rate of less than 73% (the sort percentage). Actually it is higher, at 81%.
The lower success rate for boys is because the sort process does not work as well to isolate Y sperm as it does to isolate X sperm.