I knew this comment was coming.

The SMB2 that was a direct sequel to SMB1 came out for Famicom Disk System, not NES. There's only one SMB2 that came out for NES.

Also, Yume Kōjō: Doki Doki Panic was an advertising game released specifically for Fuji TV's Yume Kōjō entertainment expo in 1987. As such, because it was just a one-off event title, they took a prototype platform game that Miyamoto had already influenced Tanabe to make more "Mario-like" (but was shelved when the Famicom couldn't run it as intended), reskinned it to feature the characters and setting of the expo, and released it for the Disk System.

So, NES Super Mario Bros. 2 was a polished, Mario-themed reskin of a rushed reskin of a prototype Mario-esque platformer.

All of that is to say that, yes, Doki Doki Panic was in fact most likely a Mario game in the first place.

I imagine they mean the US SMB2 aka Doki Doki Panic. I have actually played the "original" version and the SMB2 game is actually improved in some ways, not just reskinned. While I don't think it is better than SMB3, I think it is a great Mario game, even if not initially intended as one.