Sticking 700x32c tyres on it, along woth drop bars and a selection of other road bits (cranks, brakes, saddle, pedals) though? Are we saying that the key to an mtb is the frame, not the build or intent?
I guess it's the intent of the bike then, so I'm still screwed, there is no way I'd ride it up a mountain, ita fine for gravel tracks though.
It is still an mtb in reality, plenty of people put road gears on mtb's back in the day, or ran drops, narrower tyres etc
Gravel bikes are always going to be a dividing subject, I suppose if it was a road bike and you put knobblies on then it is still a road bike, same with an mtb and slicks, the bikes intentionally made and sold as gravel bikes, well, your guess is as good as mine.