First of all, I question the validity of the whole article, but in particular it fails to diffirentiate between the "OC/NeoTrad focuses on optimization" and previous type of play, the "forge". By all means I think D&D 3.5 was a Forge game, it was only shoved into "neotrad" because it was a blanket term for "modern games" author of the article did not like and wanted to whine about. It even shows in the name, since OC is often used in a mocking sense, to describe amateurish characters and shame young creators, often teenagers and kids, for sharing their first creations online and not being at "professional" level. It's there with "Mary sue" of useless terms in character criticism. And "neotrad" basically flattens this to "repackage of trad" and trad itself was a philosophy author of the article mocked he most in previous part. I know OP asked to engage in good faith with this, but it's hard when this is pretty much worst part of the article and clearly has least amount of respect.
So I will refer to the 6th philosophy as "character-focused". And I think it is the opposite of "trad", hencce why I reject the name "neotrad". It's like saying wet is "neodry". Character-focused type of play is one where agency if put firmly in hands of the players and, unlike classic or osr, they are less given a sandmbox and more that regardless what type of campign is being played, their characters goals and motivations are being considered when tailoring plot hooks and storylines. Players are free to pursue their personal goals and GM works with them to make quests and plotlines they want to pursue. If a character-driven style is applied to a module, characters from PC's backstory may replace specific NPCs or villains, or the PC themselves may take a role of an NPC. For example, in a character-focused Curse of Strahd game, the GM may remove characters like Ireena, Ismark or Ezmeralda and present rough outline of their backstories for the PCs to base their characters of. It ensures that if we are telling a story, it's a story where PCs are main characters, not spectators.
This doens't mean the GM is powerless in this type of play. One of important things is player buy-in. This type of game will not tolerate players who show up on a magic school campaign with "Women and Children Too" Pointdexter, Puritan Witchunter who memorized every word of Malleus Maleficarum, nor a player who shows up on a pirate campaign with a heavy-armored dwarf who cannot swim, swore sacred oath to never set foot on a boat and is there to forcibly draft entire party into dwarven army and march into the mountains, to retake long lost dwarven fortress deep in the center of the continent, thousands of miles away from any body of water. In fact, I have heard advice it may even be a mistake to come to a session with preexisting idea of a character and you should build your pcs together with other players, so that they mesh well thematically. Even more extreme approach would be to, when creating a new world, worldbuild with the players, asking them to say what concept they have and then together shape their character's homeland and people. Another thing may be to allow Instead of GM working against players or to challenge them, GM and players work to create the story together (tho GM can and should still challenge the players to keep things exciting and interesting).
Another important thing is that the world reacts to PCs decisions and actions. If they leave the city without solving the zombie problem, it will be overrun by zombies. If PCs decide to steal 100k from an NPC and buy themselves a castle for it, you let them, but the NPC may come after them or someone may contest the ownership of the castle. PC are allowed to do things with a chance of failure but without DM shutting them down or railroading, but their actions have consequences, both good or bad. In fact, this type of game encourages "success at a cost" mechanics, where PC can succeed, but something negative will still happen, thus tying their problems to their own actions.