Bomberman has always done better in Japan. This is probably in part a cultural thing, though that's just my speculation. I don't believe that fewer sales outside of Japan would cause them to stop releasing home console Bomberman games outside of Japan.

Over the past couple of decades, the vast majority of Japan-exclusive Bomberman titles were either

1) Bomberman Land games, which were largely unreleased outside Japan
2) Purely online Bomberman games for the PC
3) Mobile games

Standard Bomberman games are typically released outside of Japan even if they don't do so well out here.

Of course, now we have to hope that they actually continue making Bomberman games...

Yeah, that's true. The big problem would be the lack of dialogue translation if they keep going with games like R (although on the flip side, Japanese voice actors generally sound better).

No, I mean, given that Super Bomberman R actually had dialogue, as in characters speaking - the average player wouldn't be able to understand what's being said throughout the story if they play the Japanese version. So in the unlikely event that there is a future release that is Japan exclusive, people importing the game would miss that aspect of the game.