Really intriguing interview with Olivia; I agree that we can see a lot of the background to how the actual events of later medieval history across W Europe (including England) developed - or in the case of Alt Hist could have developed given a few 'tweaks' - from goings-on at the Valois court. British Alt Historians can sometimes forget the crucial European context to developments that on the surface seem to be a matter of internal developments at home (as with modern politics, even Brexit?).
I have highlighted a few of the forgotten French court politics effects on the crucial moments of the Hundred Years' War in my own C14th and C15th essay collection 'An Alternative History of Britain: The Hundred Years War' (Pen and Sword 2013) but doubtless I have missed others. Food for thought on some important issues in this context:
1. If royal health and inter-princely power balances among the royal dukes at Charles VI's court had been different in summer 1399, the exiled Henry of Bolingbroke (future King Henry IV), disgraced cousin of Richard II currently based in France and collecting other exiled enemies of Richard ready to invade and claim back his dukedom of Lancaster then the English throne, would not have been allowed to set sail from France to England. In OTL he was able to sail from Boulogne to Yorks and invade once Richard had taken his army off to Ireland and left his ineffective uncle Duke Edmund of York as regent, and ended up deposing R; but the French King Charles VI was R's father-in-law and ally and had no reason to see R deposed. If he had not been currently in one of his periods of mental illness or if his uncle Duke Philip of Burgundy , also no friend of Henry, had had better control as chief minister and been obeyed by local officials Henry would have been stopped from sailing; R would not have been overthrown and would have returned to England safely. There would have been no 'Lancastrian revolution' / usurpation in 1399, and possibly not at all (or until Richard, unpopular with many of his nobles as an autocrat, had died naturally and been succeeded by a child of his by his wife Isabella of France, born around 1410-15 as Isabella was only 9 in 1399). An entirely different English C15th?
2. Battle of Agincourt - the French army was led by the inexperienced but loyal young Duke Charles of Orleans , son of the Duke Louis assas in 1407 who Olivia Longueville mentions. His far more militarily capable cousin Duke John 'the Fearless' of Burgundy, son of Duke Philip and a veteran of the disastrous Battle of Nicopolis against the Ottomans in 1396 (where Sultan Bayezid wrecked the French cavalry with a hail of arrows by archers, like Henry V did at Agincourt), took his troops to the campaign but was kept out of command and not allowed into the army in time for the battle, out of fear of him staging a coup among the 'high command' - especially the fear of him by the timorous Dauphin Louis, who thus put the incompetent Charles in command. Nor did the Dauphin have the shrewdness or ability to 'rip up the social rulebook' by asking the best general (and Nicopolis veteran) Marshal Jean Boucicaut, who had the skill to counter Henry V, to take command - he was socially too junior to overrule the great Fr nobles. Two reasons why Henry V won at Agincourt and his smaller army did not get trampled underfoot.
3. Probably in retaliation for the murder of Duke Louis of Orleans by agents of Philip of Burgundy's son Duke John 'the Fearless' in 1407, in 1419 Orleanists led the shocking killing of Duke John at the Seine bridge at Montereau as he was holding a truce-summit with the new Dauphin Charles (later Charles VII) to arrange an anti-English alliance and fight back against Henry V (now controlling Normandy and heading for Paris). This ruptured any chance of a (shaky) Orleans/ Armagnac faction truce and alliance with Burgundy, and led to Duke John's son allying to Henry V and forcing King Charles VI and the royal court to join him in the Treaty of Troyes. No murder at Montereau, no Henry V success in 1420 and no English control of Paris or marriage of Henry to Princess Catherine (and thus no mental illness for Henry's son Henry VI and Wars of the Roses?).
The effects of internal French politics thus had major roles in real life C15th English history - and there are other instances too. A useful field for Anglo-Fr Alt Historians' co-operation?