If humanity died oft, we would leave quite a bit of infrastructure, that a new burgeoning species would make use of, to adapt and evolve along intelligent lines quickly.
Basic systems of bioforming. we evolved in an environment, that was created by prior life. so too, have we created an environment beneficial to intelligent life. Obviously things like advanced mechanics, houses, etc would deteriorate. but, reservoirs, roads, dumps, etc would last quite a while, and spurn faster develoment of the next species.
Trash pandas would likely evolve intelligence very quickly in a world of dead humans, but left over human civilizations.