I'm with Soldier Blue on his first point. Though, it does make sense if the characters are MHS before the timeskip since almost all of them are MHS+ after the timeskip, the statement might not be enough especially since it comes from a databook. Regardless, I'm also fine with them remaining at High Hypersonic Pre Timeskip because there have been comparable or greater jumps in AP or speed in other series.
So, if it's accepted, Shikai Ichigo would be Mach 289 and (Hollowified) Bankai Ichigo would be Mach 500-1000, right?
But since LordAizenSama has retired from his position, who will decide on this issue?