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. I just thought, why I'am I worried about games never making it outside of Japan? I just remembered that we are in the 8th generation of consoles and practically every new console is region-free (excluding the Wii U and 3DS) these days including the Nintendo Switch.
Region-locking was so back then, and seems outdated now.