Not using product management for your platform team? 3 things you need to consider:
Overloaded managers. If your platform team doesn't have product management support, the manager(s) will need to try to fill the gap. As a result, they won't have as much time providing management and leadership for the team, clearing roadblocks and keeping them moving.
Wasted time and money. Product managers are good at finding user needs and making sure the team is working to maximize developer experience. Without this focus, you run the risk of building a field of dreams.
Go-to-market missteps. With an internal platform, adoption can suffer if you don't have someone focused on the internal marketing, training and roll-out needs.
Running your platform as a product has real business benefits, but you need to dedicate the time and resources or you won't get the ROI.