I think it would really depend on how he approached things. I could see it go one of three ways. First, the women still get individual updates but their content is not optional. So using HC3 as the example Haylen and Lily would still have the exact same content, but the player would be forced to play it for the next main story quest to pop up.
Second, the women are integrated into the main plot with varying levels of importance. I've said it previously but it would make sense for there to be "pairs" of women. Again using HC3 as the example it would be easier for the game to focus on one of the two main women for each update. With each update you pair one of the two side women with one of the main women. Rose and Lily's worlds are the two easiest to mix since Rose does occasionally serve drinks at the bar in her civilian identity and the magic shop owner is part of the duke's conspiracy. Cyanna and Haylen mix easily due to the familial connection and Jazon's status as a member of the guard. It would, unfortunately, lengthen development of the story, but that could potentially be made up by not having to swap back and forth between main and secondary updates.
Third, just don't have secondary women at all. Have optional quests involving major characters just don't integrate them into the main cast. Don't give them special importance. HC2 had a handful of side women who were largely unimportant to the main quest and their lack of appearance in the finale made sense because who cares what these random sluts are up to since they have not contributed to the main story at all?
The idea you're proposing sounds interesting. It's true that it might be a bit long, but I think it's the best option so that everything feels integrated into the main story and nothing feels secondary.
In HC2, the only secondary protagonist I liked was the blonde girl, while of the side characters, I only liked a purple-haired girl who appeared throughout most of the game, and two dark elves who, although they appeared very little, were integrated very well into the main story.
In HC3, the only sides characters I really liked were the three female soldiers. Their appearances, in my opinion, felt very well integrated into the main story, and on many occasions, they coincided very well with what was happening around Cyanna and everything related to the soldiers.
I think that as such it would not be eliminating the secondary characters for HC4, rather I would say making them feel better integrated into the main story, although the secondary characters of Rose, Lily and Haylen were not bad, there were times when they felt a little out of place and even filler.