There are two ways to do product marketing.
Reactive product marketing is when product marketing is squeezed between departments. Product marketing managers react to the needs of the other parts of the organization. When product releases a feature, product marketing has to find a way to communicate that feature. When sales targets a new type of customers, product marketing has to come up with a custom presentation. When marketing is running a specific campaign, product marketing has to come up with some content for mid and bottom of the funnel.
Proactive product marketing is when product marketing is integrated across departments. Product marketing managers engage other parts of the organization to coordinate the whole flow of information: from customers to product, moving through marketing, customer success, customer support, sales. And the other way around. In this scenario, when product releases a new feature, how to communicate it is already known, because the feature was actually developed following to research promoted by product marketing. When sales targets a new type of customers, custom presentation are already in place, because the new strategy was recommended by research promoted by product marketing. When marketing runs a specific campaign, product marketing is actively involved in planning what content is needed, as well as who to distribute it to and where.
I understand most product marketing organizations are probably somewhere in the middle. Just always be aware of what type of product marketing you aim to be.
One is execution, the other is the cornerstore of go-to-market.
Which one are you?