Funny how people want to make something special.
If you think of the word monster-cross it pretty well summons up the idea of a cyclocross bike that has bigger tires. Like a monster truck which is where the term was probably borrowed from. Not that unique. Today's fat bike would be more appropriate for that term except for the lack of road like characteristics. There was probably a point where the originating gravel genre rode converted stock road or cyclocross bikes using as big a tire as they could take (which was not that big) so a different "monster" bike designation made sense but now manufacturers are creating really big clearances so that many "gravel bikes" are defacto "monstercrosses". Especially when they mimic road bikes in so many other ways (gearing, posture).
To get all divisive about what bars equate monstercross is a bit of a stretch unless cyclocross also gets that picky about which bars constitute that genre, seeing as a monstercross is intended as a big tired cyclocross bike. I always though ATB or all terrain bike was a good descriptor and what the author states a mostercross is supposed to be in the article. But he then contradicts that premise by making the parameters so narrow that it excludes many do it all bikes. It was also the hybrid concept but with a road posture instead of upright.
In the end I think the term gravel bike will fall by the way side in the same way. It is too vague in the same way that gravel is too vague. The people riding gravel roads in the mid west need a vastly different bike than those riding BC logging roads (for example) so there are times when people using the same term are thinking of very different bikes.
This is a pretty good indicator of how important it really is:
Easiest litmus test, point at the bike and ask a non cyclist what it is. You're likely to get either "mountain bike," or just "bike."