Philip the Fair and Margaret of Austria both die without issue, and the Burgundian Netherlands are inherited by the great-great-grandson of John the Fearless: John III, Duke of Cleves and Count of Mark (also Duke of Jülich-Berg and Count of Ravensberg in right of his wife).
Charles of Egmond has a single legitimate daughter, who marries John III's son and heir, putting a definitive end to the Guelders succession dispute.
The House of Mark quickly loses interest in claiming the arms and title of the Duke of Burgundy, and they pawn off Charolais and Franche-Comté to their Neversian cousins in a marriage dowry. Said Neversian branch is later inherited by a third son of the French king, who kicks off the third House of Burgundy.
(The Jülich lion gains a crown and a forked tail to differentiate it from the Flanders lion.)
Made an CoA of Old Saxony (Or in this timeline the Electorate of Saxony) wasn't destroyed as much as in OTL. I combined the CoA of the house of Ascania with the Saxon steed which was used by the House of Welfs in their Saxon lands. (More technical I used the CoA of the Saxon parliament, removed the crancelin and inserted the Saxon Steed from the flag of Twente)
if it came out of the 1837-1840 uprising, I doubt it would include the fleur-de-lys. The Declaration of Independence of Lower Canada called for equality among the "french", "british" and "indians" so a purely french symbol might look odd.