It's more like you're defending the idea of roadmaps by saying any list of stuff to do — or even saying "we're busy!" counts as a roadmap. That's not what's generally understood by the term, nor is it what the article is getting at.
I know you know what's really meant by roadmap, because your example of "when am I getting my geo?" doesn't work without a classic date-driven roadmap.
> But a lot of teams already have a 6 month roadmap because they're already committed to that work.
And those teams are inviting trouble when things pop up that override those commitments. Like Meltdown/Spectre. Or an unexpected competitor event. Or an economic change. Or a third-party intervention. Or any one of a number of things that need reasonable-sized responses and can't wait six months.
If you're working off a prioritised but uncommitted list, none of these things are problem, because you won't have allowed your stakeholders and those dependent on you to become coupled to your current 6-month view. If you have allowed them to become coupled, then you've just multiplied the organisational impact of each one of those events.
PMs should be creating decoupled, co-operative and flexible organisations where disruptive change is expected and accommodated, not tightly coupled, brittle, organisations where change is mitigated and worked around. Dated roadmaps are a symptom and a cause of the latter.