So here's the thing - I get the desired purpose of the role of centralizing GTM strategy. But in practice product managers are too far removed from the customer to be useful 80% of the time.
Basically I find that tactics that work for a given business should drive strategy more than vise-versa. This is a very unpopular opinion for sure.
In the end, messaging and positioning don't exist in a vacuum. The market responds to what it responds to. But because product marketers are too far removed from the stress of actually making messaging turn into revenue, they just don't have the skillset to be useful.
I wish product marketers could make positioning that actually works. But what happens is they make positioning that doesn't appeal to customers, and sales and demand gen pick up the slack and now have two jobs - to actually use messaging that gets results, and to make a middle manager happy with some data that helps them make useless reports upstream.