The OP is talking about seasoning that has already been properly baked on, with Crisco being the oil used to bake on the seasoning. It is possible to destroy established seasoning with high enough heat, which is why some people ill-advisedly use their oven's self-cleaning cycle (or worse, a fire) to burn off old seasoning when restoring a piece.
The relevant question is if different oils which were polymerized to create seasoning have different max temperatures before the seasoning is destroyed. Specifically, if seasoning made from Crisco can handle 500 degrees.
Short answer, though, is seasoning made from Crisco should handle 500 degrees just fine.