I believe most organizations product marketers are leverage as either Inbound PMMs or Outbound PMMs.
Inbound PMMs are focused on insights that feed the product roadmap; pricing and packaging, and product positioning that feeds into the marketing strategy.
Outbound PMMs are focused on go-to-market planning and execution of launches and adoption KPIs (The PMs are responsible for building the product/feature and their PMM counterpart is responsible for strategy and execution to drive the KPIs)
It's more of a spectrum, not one or the other, but there is a dominant expectation on what success looks like.
Most of the organizations I've worked in skew more towards "outbound product marketing".
We need to be totally in sync with our PMs, working as partners towards the same goal of building something awesome and getting people to use it. We just have different roles in making that happen.