How does mark of the abyssal actually work? Did GGG forget to change the description?

Reading forum after forum, POE forums + Reddit, various youtube videos

And still I can not make sense of Mark of the Abyssal lord
Its description in game when hovering over it and pressing alt says
Desecrating an item with the Mark of the Abyssal Lord modifier always removes that modifier, replacing it with an Unrevealed Desecrated modifier of a higher tier.

Yet I just used the Essence of abyss on a t3 affix, and the choices I got back were all less then T3...

Is there some hidden weight or level to affixes? I can't seem to find anything on POE2 Database, I'm truly confused...