No reason to reseat anyone but row 1 (and they don’t need to move if they don’t want to). Beyond that any newly open seats in row 1 can fall into the standard upgrade process.
If we’re just talking about the sides (5-9 and 17-21), then yeah it’s pretty straight forward: either leave everyone where they are or move everyone a row down (depending on how they shape the gaps for the benches), then let anyone who wants to opt out find someplace new.
The real issue is the ends and corners since they length of the rink isn’t changing. If they do end up giving sections 11 and 15 to the students, that will help a lot since the seating configuration in those sections would be moot, but that still leaves 1-4, 10, 16, and 22-24 because now matter what they do, the perspective of those seats are going to change and (with the exception of section 1) there’s going to be fewer row 0 seats in those sections than in row 1.
I’m also curious what they’re going to do with section 1 when they lower the rink. If they leave it as is, it may not affect row 1 that much, but rows behind them may have an obstructed view of battles along the end wall.