A quick search reveled that PG removers are based on NMP (N-methyl pyrrolidone) solvents.
Relying on our experience so far, we know that NMP does not have much influence on graphene's electronic properties. However, NMP molecules does posses binding affinity to carbonaceous materials such as: CNTs, graphene (depends on how rigorous the treatment is).
Moreover, liquid phase exfoliation of graphene flakes are also performed in NMP and has been observed to not hinder graphene's properties. Here's an article about the same: