Conisburgh was not attainted, but his titles were forfeited. They were then restored to his son. It would be pretty odd, I think, for him to not eventually be given the York title even if Henry V attaints Conisburgh. Assuming his father wasn't already disowned that is.
Edward of Norwich in 1414...
The senior peer would be the Duke of Norfolk, followed by Buckingham. Henry Beauchamp being created Duke of Warwick displaced Buckingham, which became a non issue with his death IOTL.
I imagine there would still be opposition to Margaret d'Anjou, hard to predict the political situation in the 1460s without having fleshed anything out 🤷♂️
I suppose it boils down to who/what takes over the position of York as Beaufort enemy #1, if it isn't just York himself.
Richard of York's territorial presence largely came from the Marcher inheritance; Edmund of Langley was the poorest of his brothers historically speaking, and while the 2nd Duke of York enjoyed more favor land grants in his favor were rescinded IOTL by Henry IV from what I can remember offhand...