In a statement on Reddit, Konami clarified what the R in Super Bomberman R means:
R is a throw back feel for the Devs. to when games could simply have a letter and allow that letter to carry many meanings.
It symbolized Returns & Reborn because this game is such a homage to SNES and SB3.
But it also mean Rangers, to represent the diverse and colorful group of Bomberman characters who patrol the galaxy.
While it’s not a straightforward meaning, it definitely invokes the feeling of classic game titling.
Super Bomberman R is a launch title for the Nintendo Switch, releasing on March 3rd.