Exactly the reason I gave to minimize costs. Do you remember? Businesses try to make it happen within the fiscal year and use tax breaks to cut costs. Schools and other government entities can schedule it around replacement.
When the Marine Corps switched from C-rations to MRE's, they didn't dump the C-rats. We ate them until all were gone. I was eating 1968 C-rations in 1984 Korea.
Literally apples to stationary comparison.
Schools have little flexibility. All these changes will likely be for the next school year but the window is limited same with businesses/individuals on a street that changes.