You read the headline correctly, it is indeed a new entry in the Street Fighter II series which last saw a HD remaster/remake on the Xbox 360 and PS3 as Super Street Fighter II Turbo HD Remix back in 2008. When clips of a Street Fighter game were shown during the Nintendo Switch presentation, I assumed that the system was basically getting a port of that 2008 title. Little did I know that although it looked similar visually, Ultra Street Fighter II: The Final Challengers is an all new title for the Nintendo Switch (and an exclusive so far).
It looks to share the same visuals and engine as the 2008 HD remaster, but as the title suggests it will add new content, in particular the “Final Challengers” that are apparently just Evil Eyu and Violent Ken (last seen in SNK vs Capcom: SVC Chaos). Who knows, maybe there’s other characters yet to be revealed.