Potato, the abarbanel(used in messianic circles ad nauseam) says that moshiach might be from those who rise during techias hamaysim, anf tzaykuntzus that gemara – no one ever sair moshiach will be the lone resurrected one. Not the gemara, rashi, the rambam, or anyone else.
He invented the techia protis thing; no one says it clearly.
And rashis 2nd(and preferred) pshat is that the gemara is talking about examples of who moshiach will be compared to.
Eliyahu doesn’t have to be resurrected because he never died, as evidenced by the pesukim and thousands of encounters yidden have had with him all throughout history.
As for the medrashim, check out the meforshim who this guy ignores. It’s simply explained that the neshoma of moshiach was around flr thousands of years; he embodied people like dovid, chizkiyahu, etc…who were bona fide moshiach candidates. But they individually were not moshiach, since the geulah did not happen in their times.