Elaida at this point is likely out the series for good. There's no rescue awaiting her, and even if she were to return to the WT, she wouldn't be reinstated as Amyrlin. She'd be lucky if she weren't stilled. The Hall and perhaps all the AS have essentially blamed her for the Seanchan attack, and this is on top of all the other blunders and problems she's caused as Amyrlin.

Whatever terms and agreements Egwene and Fortuona negotiate, the return of Elaida is not likely to be part of it, unless it's part of a broader prisoner exchange, that is captured AS in exchange for sul'dams or damane in AS custody. Even then, the WT might decline to take Elaida back as a punishment for her failures.