There's not much to talk about.Originally Posted by MFauli
Falco is an Eldian who has shown that he understands more than just Glory for Marley!. His family originally intended to revolt against Marlian rule, and he's serving as a soldier to perhaps save them from being culled. He has enough rapport with Eren to date, and is perhaps about to be in a position to hear/understand the perspectives from both parties.
Eren will not die old, from what we've been told so far. By the time of his retiring, if he encounters a candidate who would use the Attack/Founding Titan for a purpose that Eren would also agree with, then it'd make sense to pass the power onto them. The only young candidate who might fit this bill is Falco.
I did say that this scenario would only make sense if Titans were expected to exist for a further generation. If they were to disappear during this cycle then passing on the power is not required.