I think anything that promotes more pinball among pinheads or potential pinheads is great.
You can think it sexist but there are in fact genetic and evolutionarily selected differences that are predisposed advantages provided to men over women when it comes to reaction time/hand-eye coordination.
This not saying that there are not some amazing women players in pinball (like all sports/games), but that when you overlay the spectrum of player capabilities even when adjusting for other social variables (i.e. current male/female ratios, experience, number of competitions) these scatterings will be disparate, with men being higher on the ability spectrum.
Some of these abilities are likely conferred from social societal differences as boys tend to focus on many hand-eye coordination activities as they grow up.
Regardless of what actually causes these differences in abilities they are apparent.
I say it is a great idea to offer a women's only PAPA division. It is no different than offering a juniors/seniors and if anything I would say their is more data and reason for a women's than a jr/sr given that many of the jr/sr players are already competing at the A div and there is no data to support/ justify these extra placements.
It is my understanding that Jr/Sr divisions were/are intended to promote pinball to groups that are thought to not have the skill yet/ beyond their peak (whether due to age or experience in these divisions). if that is the case then they should have some IFPA and past papa performance restrictions also. I would say if you previously finish top 24 in A/B/C or are top 400 IFPA then you probably should not be playing in the separate divisions of Jr/Sr/Women as you have already proven you are not in need of a seperate division based on genetic/age/ experience differences.
All the above said, I am not a women so I can't tell you how a women would feel about it other than the fact that my wife is a pretty active competitive player and wants more women based events.