I think that they will still have Chansey and Growlithe with them. My reason for saying that is because some people have Pokemon that are unavailable in RS and they are in AG.
*SPOILERS*
Some examples are that Brock only has Forretress with him, and Jessie used to have Arbok with her.
*END SPOILERS*
But if they don't have Chansey and Growlithe, maybe they'll have Poochyena and some other Pokemon.