I'm going to go out on a limb and guess you're not too familiar with the
French Wars of Religion.
Sorry, but that kind of response to a question like 'do we really need greater english influence in france for this' make me think the same about you.
Sure, greater english influance in France could ( not even sure ) result in protestant France, but so could a lot of other things.
From the affaire de placards to Henry II position, Conjuration d'amboise to Surprise de Meaux, various tumultes and battles.. etc, there are quite a few PoD which could result in a protestant french king and court. If this happens early enough ( Henry IV is too late, IMO ) then there's a good chance for France to become a majority protestant country.
My favorite PoD is to have the regent and court become protestant by reaction to a botched Guise attempt to kidnap the young king Charles IX in 1561. Moderate catholics and protestant then crush the Ultra-catholics and royal favor ensure that protestant dominate and so most of the mobility and bourgeoisie convert; campaigns will take longer.
No english influance needed.