Uuuuuugggghhhh
Planned Parenthood (the 501(c)(3) organization) is by law not allowed to give money to support candidates. The Planned Parenthood Action Fund (the 501(c)(4) organization that supported Northam), however, is allowed.
The laws separating these organizations and what they can and cannot do are VERY strict. They may share the same ideals, but they do not share financial resources. That would be breaking the law, and as closely as people scrutinize PP, they can't afford to break the law. That $30m spent in 2018 was from the (c)(4), not the (c)(3). There are NO public (federal, state, OR local) funds that go to the (c)(4).
Bottom line: "defunding" PP will not affect the (c)(4) at all. If anything, it'll help them - people who support PP will give more to the Action Fund, to aid in lobbying to get that "funding" back.