Grookie is with Lycanroc and Riolu in the ending. If anything it means he's going to Ash.
And besides, Grookie is the type of Pokemon that fits Ash's personality.
No, it means nothing, since it was just Japanese wordplay.
Because i can do the uno reverse card: Since Ash was talking over the Sobble section, if anything, it means he's going to Ash (And we all know how that turned out).