I don't think dividing the possibility of battle system between "RPG" and "action" is correct analysis.
First, FFXV is not an action game, aside from the fact that you control the character around the field. It's very much an RPG that plays out fast-paced in real time. That makes it more of an RPG than something like Skyrim (which is also still an RPG). With the speed at which you enter commands, and the auto-battle nature of it, you might get the mistaken impression that it's "action", but the emphasis is on strategy of commands, not technical dexterity on the control pad.
Second, I think FF has always evolved the RPG genre and I do not see XV as any kind of hard break from that tradition. Going back to the introduction of the ATB bars in FFIV, that too was a step away from actually being "turn based" into more of a "real-time" battle scenario. XV just seems like a similar transition towards "real-time" begun in IV, the only difference being a matter of degree.
I do think this series has continually innovated new RPG configurations, and has never been a tradition-beholden series unless explicitly stated (IX, 4 Heroes of Light, etc). Tabata is right.