Class Registration at UCI via University Registrar - Why did the Maximum Class Size Decrease?

Colleges and Universities A-Z University of California - Irvine
1

So I was using this tool https://www.reg.uci.edu/perl/WebSoc to view class schedule for Fall 2016 and noticed that the Management’s maximum class size decreased from yesterday, (Tuesday 5/24) to today.

For example:
Mgmt 101 Max was at 90 on Tuesday, now it is at 30
Mgmt 102 Max was at 90 on Tuesday, now it is at 55
Mgmt 109 Max was at 70 now it is at 50
Mgmt 131A Max was at 70 now it is at 50
Mgmt 132A Max was at 70 now it is at 50
Mgmt 151 Max was at 67 now it is at 25

Is this a common thing to reduce class size while later registration windows are opening for UCI or is it just something some of the UCI schools, like Merage in this case, do for specific reasons that are relevant to the school?

Any transfer students out there that are nervous about this practice? Any current students that can tell us more about it? Thanks.