If that is true in any way whatsoever, that is a completely moronic long term goal. Lemmy devs themselves have encouraged instances who do such a thing to defederate. I don't see how realistically advertising or monetization would be done not only without immense privacy concerns that would likely affect the rest of the fediverse but without major protests and mass defederation. The backlash against it would be immense, not just on lemmy but across the fediverse itself.