>>6163391Even if the theories are true, Jon have not been acknowledge by his parents ; therefore he forever is, except by gaining a royal decree, a bastard.
And, bastard don't have legal claims on thrones, even less when they are unknown and powerless (the scattered army of the north that his name could bring isn't suffiscent to march on King's Landing).
By the laws of Westeros, and thanks to his lineage and his brother's coup (that have been recognised by the ruling houses of the country) Stannis is the King ; by the laws of life, he is merely a pretender, with an insufficient army.