That's about as meaningful as needing to know whether an enemy did a ranged, melee, close attack, or what defense they went against in 4E, or whether they used a spell-like or supernatural ability in 3e. Information you need to know to figure out what defenses apply, whether you can do any immediate abilities, etc... but ultimately some people will skimp or elaborate the details as they wish.
The scary thing is, people do the same thing in the systems that have less mechanics, or mechanics more oriented on story.
The linked Ron Edwards article just talks about game systems catering appropriately to their GNS goal. It's a little dated, but here's the thing - none of those three concepts is exclusively roleplaying. The simulationist can have a complete immersive break as the narrativist hyperfocuses on the plot and the gamist can really dig into elaborate description of his badass attack to get a string of circumstance bonuses to his roll.
System does matter for how much you're enjoying the game, and how well your DM or particular group works with it... but it doesn't have a tremendous effect on the level of roleplay beyond that assumption. Different groups have wildly different responses to different games, of course, so the system makes a big deal in that respect. Some players, for instance, don't get into characters in simple games cause they don't have enough fiddly bits to inspire them to think about the characters. Other players are overwhelmed by the level of detail, number of attacks, math involved in complex games and lose interest in the actual character beyond all the numbers. Some players are so goal oriented that they will never roleplay unless there is a mechanical benefit for doing so, but if there is might roleplay up a storm. Etc. Similarly, some DMs are inspired by the act of working through all of the options, tables, etc for a complex game, generating ideas through the work of dealing with the system. Other DMs get bogged down and never get past the minimal "Ugh, need to generate a level appropriate combat, which means looking in this book, then that one, cross referencing this...", so don't spend any time working on plot hooks, integrating with character stories, etc.
It's a pretty complex subject. Anyhow, SRM's got some interesting stuff there.