The self-selection of Lemmy vs Reddit users is an inherently stratifying medium. Lemmy is also distinctly left-leaning in a way that Reddit is not.
Having experienced several waves of Reddit absorbing Facebook exoduses, and the subsequent worsening of experience, I can only infer the same pattern will exist in Reddit slop migrating to Lemmy.
If anything, I'd prefer that entire crowd return to Facebook to bloviate their opinions and Boomerisms ad naseum.