Have you really seen 59.99? Sorry to say, I doubt this. Legend averages come with three digits, one of them unseen. 59.99 would have been less than 59.995, in fact 59.994 or less.
Fact is, one shot is worth 1/500 = 0.002 on the average, thus that 60.00 that you've seen actually may not have promoted you because it was a 60.002 or 60.004.
To get from 60.002 to 59.994 is a four shot drop (4/500 = 0.008). Thus, a 32 / 64 would have been in the average pot - possible but unlikely IMHO. The quest for 29s and 30s might create enough 31s to kick them out.
Fact is that all of the previous promotions take place at x.00 - seen a few of those. Why should it be different on the brink of TL?