This is only accepted by people who hold similar opinions of LPD & EaV. Those who admire both are eager to equate their modern heroine with the legendary figure and thus justify her intransigence. Those who are a bit more critical of both like to equate two similarly over-rated failures. Some of us in the latter category see no reason to assume that this makes them necessarily incarnations of the same soul. The only one even remotely suggested by the books is the Birgitte-Teadra, which doesn't count, since she was not reborn in her current incarnation, but is rather an incarnate ultimate version of that soul.

EaV/LPD is actually more often, IMO, referred to as a repetition of roles vis a vis the Dragon, rather than a reincarnation. I suspect more people have subscribed to insane theories linking Elayne & Ilyena due to similarity of names & hair color, then have made a plausible case for LPD being reincarnated as Egwene.