I very much doubt that they’re using Legacy.

Legacy’s best bet at being legitimized by Lucasfilm was pre-sale, when Lucasfilm wasn’t interested in spending too much money, and wasn’t really wishing to allocate much budget to original version pursuits. In that atmosphere, a freelance film restorer making a pitch that he’ll do the work at a low cost for them is attractive. This ignores, however, that Reliance was already contracted for (and delivered) their own 4k restoration of the 1997 SE negatives (which were then updated to replicate the 2011 blu-ray versions) shortly before the sale was completed.

Post-sale to Disney? Theres’ no reason for Disney to entertain the same pitch, because not only do they already own all the elements they’d need to restore the original versions, but they have access to some of the finest (if not THE finest) technical facilities for film restoration in the business currently, and have no budgetary issues, self-imposed or otherwise, to worry about when it comes to that restoration. I don’t see a possibility existing where Verta, on his own, could create a salable product that could compete with what Disney could do in-house, much less Disney choosing to forgo their own in-house work for Verta’s.

edit: Whoever is making that twitter thread is being pretty irresponsible w/ their speculation there. I can understand WANTING it to be evidence that LFL is using SW Legacy. But it honestly doesn’t make sense to extrapolate from those two shots in a tie-in book that Legacy is now official product.