It's a triple threat.
Update: These games are now out, update today!
Usually, by now this month’s NES Online games would have been announced. With Golden Week in Japan, it kinda got skipped over – but that didn’t stop Nintendo America posting them up on their website today.
According to the upcoming titles page on the Nintendo Switch Online section of their website it is;
We’re going to wager that it’s those three games for all regions, seeing as VS. Excitebike didn’t come to the west and was only released on the Famicom Disk System.
Also more on Pokémon Presents, dead Gold Coins and more.
Because Gate Rune and Dunan Unification War is too long to fit in a title.