Depends how far writers are willing to go with them. End of their mission with Meloetta and Kami trio left things open ended with Jessie, James and Meowth not really leaving in way which you could call someone conclusion and Giovanni wasn't defeated with crime organization still posing threat.
Which implies how story with TR organization isn't over yet and how true climax is saved for later.
Return to Kanto also implies that either Ash and co will go there after league having final confrontation with them, or that Giovanni defeat and disband of whole organization wont happen until very end with Jessie, James and Meowth being given new mission which involves following Ash again. Which as much to someone disappointment in theory could happen.
But really only possible way to justify TR further stalking of Ash which avoids going back solely to comic relief(slash regression) is if they remain more skilled and successful in their attempts, ending as part of their new mission handed over from Giovanni not serving as cheap ploy device anymore which tries to catch yellow rodent.
After all you can have both competent and goofy antagonists.
Few episodes ago i was almost positive how BW will indeed be end of Jessie, James and Meowth with all guidelines pointing toward that. But after rather rushed two part with Meloetta and Giovanni slipping away from hands of law again, opens window for TR possible stay in show for time being.
Unless whole retreat of Giovanni with his loyal servants was supposed to be writers "big finale for TR", which wouldn't make any sense leaving them to continue with their malicious plans in pokemon regions not providing any sort of ending for JJM trio.
Than again writers are horrible at giving proper closures to characters once they're gone leave things open(Misty, Brock , Ambipom etc comes to mind), and not so great writing in current BW increase my skepticism even more.
When looking back Jessie, James and Meowth has been in this show from start gaining massive popularity over time becoming timeless in pokemon series, so for that reason alone its hard to believe having them replaced and gone forever before show ends.
But than i start remembering when people thought how original female will never leave, how Brock long stay ensures he will be with Ash until very end etc and they still left.
Nowadays we know how long stay, popularity and iconic status means nothing to writers, so TR departure is very possible.
Unfortunately in most cases character leaving in this show means being gone forever, which i hope wont apply to Rocket trio not ending erased never to be seen again.
Even so popularity of character doesn't play role in his leaving, with TR being already put in consideration to leave after Johto at some point judging by mr. Shudo blogs.