Just speculating out of ignorance, but:
I'm not sure where the idea of building pyramids orginated, but maybe if this Red Pyramid hadn't been built, later Pharoahs wouldn't have felt obliged to build large pyramids themselves. Fewer, smaller, or no pyramids could conceivably lead to fewer slave revolts (were there any connected with pyramid construction?) or fewer slaves.
Were Egyptian slaves primarily from POWs, or were domestic populations a large contributor? If POWs, then they still need to do something, unless they're simply released, so maybe they could go towards building some other projects, like dams, canals, awesome palaces, &c. If slaves were of domestic origin (same is true if POW-slaves are released), maybe the Pharoahs just wouldn't take as many slaves, and with the money saved from feeding and housing slaves and from using much less building materials, not to mention with the could-have-been-slaves doing some more beneficial work, the Kingdom could prosper economically like never before.
I could speculate more, but i'll stop here.