No it wasnt, it was a clear warning from deus which xanthe forwarded to dexter, and i dont think it was related to her powers (deus would very probably know that she gets powers anyway tho, like he does with her sister) but about her taking the chair of their dynasty from dexter which apparently goes along with dexters death.
Dexter wasnt surprised at all and more like its what he is expecting tiffany to do, like he raised her to become like that. Like a sick twisted milkken family tradition/test where you have to be able to put your father down to become the one in charge.
I suspect dexter handled his father in a similar way and is actually looking forward to tiffany making her play and stepping down/dying, these milkkens are crazy fucks
He immediatly stopped xanthe from explaining further too and told him to mind his own buisness. He knows about tiffanys intentions because hes the one who groomed them imo
