Some wonders and obsolescence

[Event Horizon]

Since I'm adding more techs, buildings, etc. to the Future Era, in order to extend gameplay, I'm thinking of making the Pyramids obsolete... Since they allow all government forms, and I've added a new Government Civic later than the obsolescence... What if I adopt that new Civic and suddenly becomes unavailable via the Pyramids? Am I risking a CTD if that happens? Does the game handle it?

Many thanks.