WI Anne Boleyn has a healthy son who survives long-term? This would probably be in late 1534 or early 1535.
Go and read Now Blooms the Tudor Rose on this website.
My sig TL actually has a stillborn son of Henry VIII and Anne Bolelyn surviving and is named Richard IV. If Anne Bolelyn's stillborn son does survive his childhood, there won't be a need for Henry VIII to continue seeking new wives and then when he dies and Anne Bolelyn's son succeeds him as the new King of England, he'll have a very different policy.
Of course, this can also result in Princess Elizabeth Tudor being married to different princes, from Robert Dudley to even Tsar Ivan IV.