I knew who the author of this thread was before I even clicked it. ;)

OP: Tbone, this has to be your best one yet. I mean, this is a REAL longshot. the first game sold 5 million altogether. But, 5 million in one region? Well, it's got the handheld component going for it, thanks to the Switch. Plus, a much longer shelf life to work with.
But ATM, I'm going to say no.
Not to say it can't be done, because Animal Crossing: New Leaf has done it, and I'm sure that Pokemon X/Y has done it.
It has a chance, but that chance is very slim.

Hardware Comparison Threads:

PlayStation 4/Xbox One/Nintendo Switch: 2019 vs. 2020