In the Forge sense, I think neo-trad is a species of high concept simulationism, or in some contexts perhaps it is exploration-heavy gamism where the stakes of "loss" for the player are very low. But in establishing exploration (in the Forge sesen) as its primary concern, or as a significant concern, it uses a different authority structure from that present in the examples that Edwards talked about 20 years ago. This different authority structure is partly a matter of "ethos" - centring the
player more than is traditional - but also is established and mediated, at least to some degree, by new techniques that have been developed, or at least become mainstream, over that two-decade period.
This blog -
What does it take to be a “neotrad” role-playing game? - identifies some of the techniques that are present in neo-trad oriented RPGs but absent from trad-oriented ones.
Asymmetric gameplay; a "Chekhov's gun" approach to mechanics; "bounded bookkeeping" and other means of supporting the GM's role in framing and adjudication; and no rule zero: these are primarily about rejecting the purist-for-system design legacy that remains common in many trad-oriented RPGs. By making the GM's job easier - with more support/scaffolding for decision-making, and reducing the technical challenges inherent in implementing a decision (for instance, no need to have drawn up complex maps to support wargame-style action resolution) - these also permit the shift of authority towards players without that impeding the actual processes of play.
Clear agency for PCs and shared party creation: these mean that "world/setting exploration", "fish out of water" PCs, "hunting for the adventure" and similar aspects of much trad RPGing are foregone: the focus of exploration shifts to character and situation, where the situations are clearly drawn. In addition, these technical innovations further support the realignment in authority to players, without that realignment pulling the rug out from under the GM, because the GM can see what the players' concerns are and can know where they are heading in the play of their PCs.
The incorporation of these techniques is summed up thus:
"it’s got the production values, ease of use and plentiful campaign material of a traditional RPG, combined with the kind of clever and thematic rules design usually found in the indie games”, he said. . . .
a tabletop roleplaying games need to be abreast of the times, requiring less time and effort, cutting downtimes, taking some useless responsibilities away from the master job and, generally speaking, be competitive with other entertainment media. “Modern” RPGs (or indie, or new wave) are a very good answer to these needs but they offer a different game experience so many gamers are not comfortable with their approach.
That "not comfortable" is about departures from sim, or exploration-heavy gamism. Neo-trad remains in the "comfort zone" but changes the ethos and techniques.
I think understood in the above terms, neo-trad is broadly identifiable as a thing: an ethos/orientation to RPGing that certain games set out to support.