Thats a good point. We should design the system so that it can be adapted to population changes with planned transitions and levels of support, no matter what generated it. However, we should probably not base a funding model intended to run for multiple decades around an edge case like what happened during Covid.
if you expect your funding model to span multiple decades then yes, you absolutely need to factor in “edge cases” like covid. climate change will have an effect on school attendance, guaranteed.
any system that seeks to create an “efficient funding” model will always fail our children. schools are not businesses and cannot function as one.