Are they actually running the Apple playbook in reverse? It seems to me that they're actually running Apple's playbook pretty squarely, just in another domain.

First-gen product that seemed to not know where it's going? Check.

Continued quiet iteration behind closed doors despite first-gen being a flop? Check.

Sticking with the product line over many years, where most other companies would have written off and thrown in the towel? Check.

Multi-pronged GTM strategy where other products prove out key bits of next product? Check. (see: SteamOS and Proton setting the stage for Steam Deck, which in turn sets the stage for Steam Machine 2)

Deep software-hardware integration in ways that are highly salient to users? Check (see: foviated streaming for Steam Frame, Steam Deck "just works")

The "in reverse" framing was largely in reference to the fact that Apple built the software ecosystem after getting loyal hardware consumers, whereas Valve got loyal software users first and is now selling hardware to them.

Otherwise, I do think a lot of what you say is true, and some of it is in the article (e.g. the software "just works").