Wars of the Roses are 50+ years from the POD, no guarantee they'd eventuate. Even if you assume that Henry V still dies on schedule, and none of his brothers still have no issue, the existence of another extant branch of the Plantagenet family would change the dynamics of Henry VI's regency somewhat.
In the short term, there'd be potential for tension between Humphrey and the Lancasters over the Bohun inheritance- which remained something of a live issue for several decades IOTL (desire for the other share of the Bohun inheritance may have partly motivated Humphrey's great-grand-nephew's support of Richard III, IIRC?)