Said this a billion times, but the soil the stadium is on isn’t very stable and can’t hold much weight. It is why the entire structure of rows is made of lightweight steel and not concrete.

I don’t think there will be any major renovations as far as replacing sections go. There will amenities added here and there to extend the life of the stadium. I think the end result will be a completely new structure across the street or somewhere else.

Any new stadium would require concrete which means the soil has to be stabilized with stone columns and very deep pile rods. Concrete lasts longer and can be repaired and replaced easier than steel rows and sections. Given that BYU pays for things first my guess is it has a stadium replacement fund or will announce one in the future to save up the $1-2B needed.