I dunno that it's a counterpoint. The thesis of the article is that setting up a user onboarding flow before you're ready is a waste of time, and/or that it's not as useful an activity as others you could be doing with that same time.

I'd consider Polar a success of "adding onboarding when ready." I just don't want people to consider onboarding as the first and only tool to reach for when trying to fix your Trial-to-Paid Conversion issues. There are a lot of other useful tasks you could - and frequently should - be working on as well.