Monster Boy is a great game, but I'd say that falls firmly in the "A" camp. I'd also argue against the assertion that AA games are going the way of the dodo. Studios like THQ Nordic, Focus Home Interactive, Paradox, Sega, Atlus, NIS, and Bandai Namco are still turning them out. Nintendo publishes a lot of AA games, also.
Some of my favorites from the last few years are:
The Alliance Alive
Ys VIII: Lacrimosa of Dana