Is Fury the Lineal Champion?

That's the trickiest question involving this matter. Based on various historical precedents, I'm inclined to say somewhere in the 3 to 5 year range.

I addressed the Lewis hypothetical in my video, and if he came back, I think he would have long lost his claim. There is no precedent of a retired lineal champion returning to action after 15 years of inactivity. Citing the figure above again, 3 to 5 years isn't historically unique. But 16 years is another story.

I think the best comparison here is when Ali fought Frazier. When Joe defeated Ellis, a new lineage technically starts, but there were ALWAYS going to be question marks regarding Joe's reign as long as Ali was permitted to return, which happened mere months after Joe established his new claim. So there was always going to be doubt in that situation, but fortunately Ali and Frazier were eager to do battle, which resolved that matter, and Frazier cemented his claim when he defeated Ali in the FOTC. But had Frazier never faced Ali, there were always going to questions about Joe's legitimacy, and the same situation would be applicable if Wilder vs AJ happened and Fury returned soon after.

Yes, as I mentioned in the other thread, had Seferi won, I believe he almost certainly would have gotten a lucrative payday against Wilder or (more likely) Joshua.

I believe he most certainly did. He still never lost in the ring. And the #1 and #2 guys prior to his return had no real interest in fighting, so that just strengthens Fury's case.

Put differently, until someone beats Fury, any other claim will have questions - much like in the situation with Frazier had he never faced Ali (or Ali's would-be conqueror in this hypothetical).