I am a "Group Product Manager" and at least on skim, this article doesn't seem crazy. I would expect myself and folks on my team to articulate these things - or call out when we don't have something for a good reason (eg we're making a speculative bet.)
The thing that I don't expect is that the roadmap would stay static. Reality changes over time, you encounter new customers and opportunities, learn what's harder or easier than you thought, etc. So I would say "this is what we have today" and if that evolves somewhat even a few months down the line as we learn more, great. But at any given point, you should be able to articulate your best understanding in something that does hit against these checkpoints.