The Legion Panel at NYCC has just come and gone, and there is one or two rather interesting bit of information coming out of it.
As you may or may not know, Legion (or David Charles Haller) is canonically the son of Charles Xavier. This has lead to a lot of speculation surrounding the TV show, as to whether the on-screen character will follow this route. Well, it seems like it might be alluded to at the very least. Speaking at the panel, creator Noah Hartley mentioned that the connection will be brought up at the very least.
However, whether we can expect the character to be the son of the Patrick Stewart version of Professor X, or in fact if the show is tied to the cinematic franchise at all, Hartley said that a certain amount of the "is to be determined".