If you wonder if any historical discoveries or speculations about the legitimate or otherwise birth of medieval persons can affect the claim to the throne of the present British monarch, the answer is no.   Her claim to the throne begins with the events of 1688, and no prior historical events can make it stronger or weaker.  If the world began in about the year 1550 it would not change her claim.

After the childless King William III and Queen Mary II usurped the thrones of England, Scotland, Ireland and France in 1688-89, the English Parliament passed several laws restricting the future succession to the throne to the nearest Protestant descendant of the Stuart Dynasty.  They included the Bill of Rights of 1689 and the Act of Settlement of 1701.  When England and Scotland united to form Great Britain in 1707 the Protestant succession was reaffirmed.  Thus in 1714 George, Elector of Hanover, became King George I of Great Britain, Ireland and France.  In 1801 Great Britain and Ireland united to become the United Kingdom.

Since 1714 every monarch of Great Britain or the United Kingdom has been the legal and rightful successor of George I, who was the nearest Protestant heir to the Stuart Dynasty as mandated by the Bill of Rights, the Act of Settlement, and other laws.

Unless, of course, some rumored royal secret goings on were correct.  King George IV, for example, was a bigamist, and it is unclear which, if either, of his marriages was legally valid.  And Mrs. Fitzherbert, his secret wife, never answered the question of if she had any children with George IV.  

Queen Victoria, the niece of George IV, was rumored to worry about someone claiming the throne as a secret child of George IV.  James Ord, father of US general Edward Otho Cresap Ord, was rumored to be the son of George IV and Maria Fitzherbet.

But until and unless some proof of any such skullduggery and hanky panky turns up, we have to accept that the British throne has passed from rightful heir to rightful heir for over three hundred years.  Thus the present monarch, Queen Elizabeth II, is the rightful heir of all previous monarchs back to the invading and usurping pair William III and Mary II.  And only that far back, unless one totally accepts the ideology used to justify their invasion and usurpation.

If someone does not totally accept the ideology used to justify the invasion and usurpation of William III and Mary II, then one will tend to believe that Duke Franz of Bavaria is the rightful heir by genealogy of the Stuart, Tudor, Plantagenet, Norman, and Bruce Dynasties that ruled England from 1066 to 1688 and Scotland from 1306 to 1688.

And that the heirs of John I Balliol are by genealogy the rightful heirs of King Malcolm III of Scotland and his successors until 1290, and also the rightful heirs of the Anglo-Saxon kings of England of the House of Wessex.  And that Karl von Habsburg is probably the rightful heir by genealogy of King Harold II Godwinsson.

And Mr. Evan Vaughan Anwyl of Tywyn (born 1943) may be the rightful heir of the kings of Gywnedd and Kings of the Britons.

Anyway, it doesn't matter to the present Queen Elizabeth II whether any royals reigning before 1688 were of legitimate or illegitimate birth.  Her claim to the throne begins with the events of 1688.