hmmm ... ok. I don't seen a succession protocol for these folks.
I think it more about personality, ergo cult of personality, than bloodlines. They like the narcissism (even though they don't know what it is) ... greatest ... bigger than life .... sucking ALL the oxygen from living humans ... and absolutely make it about Trump. The rest of the family is run of the mill rich people egos, but none of them as far as I can tell are narcissists. That is the one big appeal as a person i.e. he can grab women ... double down on it and they don't care.
Of course the message is important i.e. the politics of division and he is a "master" of media manipulation. When Trump bloodlines try this, they sound and appear anemic. It looks fake ... contrived. The faithful believe it was stolen only because Trump said it. They don't care that the Kraken Lady says she lied.
While I have seen the Trumpite who wore a shirt with the lineage on it, I don't think he has an audience or paying customers who would buy that shirt.
Currently I think should Trump die, there would be a mad scramble to anoint oneself as the heir of Trump's ignorance. Cruz, Hawley, Green, and all the other nuts will say, Mr Trump gave his blessing to them. They were true believers in the Trump message and his persona. I don't see anyone with the wherewithal to assume Trump's role in the same way as Trump did.
I think there will be a lot of aimless people looking for the next demagogue, which does not bode well of the health of American Democracy.