Jordan is a defacto Palestinian state by another name in any case and it has relatively good infrastructures as far as I understand and that can make life easier for the Pals.. Egypt must already be the life line for Gaza natives and they can access a bigger market through them. Perhaps a dual Jordan/Eygpt citizenship for all Pals can be an insentive for all parties as it would also improve the commerce between Jordan and Egypt..
You know, I believe that Pal hard liners will appose it before the other two states because the apposition tradition is embedded under their skin...
Of course Israel would like to "dump" the Pals they drove out somewhere, rather like NYC desperate search for someplace to put its garbage. Not a nice image for Israel. And due to its policies of apartheid, it won't allow Pals to return to their former homes. That is ethnic cleansing by default.