Meltzer/Alvarez, so, grains of salt and such.
Penta has said he wanted to do a WrestleMania before he retires, and is about to hit 40 so this could be his last shot at a WM contract if so.
The other side of the coin is that the Lucha Bros have a lot of side-hustles on the go that I don't think WWE would let them keep. Penta does a lot of Mexican indie shows, and they run their own "Republic of Lucha" merch store too. They'll have to weight up the value of their all their outside gigs (and a potential AEW offer) against the WWE offer.
I'm glad I got to see Penta do his thing in Lucha Underground, and the Lucha Bros AEW tag run was decent. As long as they're happily getting that money, it's all good, regardless where they end up.
They were my favorites in Lucha Underground and a big reason I started watching AEW. I'll be sad to see them go but I can't blame them if being on Mania has always been a dream of theirs.