And if the all the senior Valois lines die off like in OTL
It would ask for three lines to disappear in a row : Valois-Orléans, Valois-Angoulême, Valois-Anjou were closer (and the still possible newer allohhistorical branches). Valois-Bourgogne possibility to take the crown at this point were meager.
Other than that, I agree with Janprimus : even if Louis XI is still pretty much likely to go for Burgundy proper as well several parts of Burgundian lands in the northern part of the kingdom (Somme is a no-brainer, and he did have the forces and ressources to undergo this), Burgundians are still going to hold their ground at the very least in Netherlands, probably elsewhere as well.
Interestingly, the presence of a strong Burgundian/Netherland principality may make Italian Wars if not delayed, at least less of a focus : IOTL, Valois went for Italy after making sure there was no direct conflict in France proper. I'd think the Burgundian presence may be changing this there (and indirectly, a continued hostility in Spain, for different reasons), making expansionist ambitions in Italy less important and maybe more prone to negociations (Maybe more focus on Savoy and Northern Italy, would it be do keep new conquest closer to other geopolitical focus?)
Henry of Navarre in 1589 was accepted after his conversion to Catholicism despite being only very very distantly related to the last king.
But, and that's an important point, while he was the closer male relative to Henri III, the last king acknowledged him and Henri of Navarre beneficied from the alliance of Protestants, moderates, politiques, etc. factions.
And even there, as you said, he wasn't accepted widely before making several concessions to other houses.
It's not about an automatic succession, playing smoothly, but about political concerns that would, I'd agree, favour the more close relative.
Salic Law is very powerful in France in the 16th century. Why do you think Henry IV became king at all if not for Salic Law?
Salic Law is an improperty. We should mention the
Lois Fondamentales du Royaume, whom parts were more or less justified by the old Salic Law that virtually disappeared by the late Middle Ages.
Thing is the
lois fondamentales were extremely dependent of the situation : there was no clause of catholicism of the heir before Henri IV had to convert. If the situation turns like there's a political impossibility to make Valois-Bourgogne kings, you'd have new clauses appearing.