I sent an email to Sega Support not too long ago asking about if they could work out a deal with Konami to have Bomberman in Crossworlds and this is what the person at the desk told me
"Hello ,

Thank you for sharing your experience with Sonic Racing: CrossWorlds!

We appreciate the time you have taken to share your enthusiasm and feedback on having Konami's Bomberman as a playable DLC racer.

While we are not able to confirm anything further, your input will be shared with the team.

Please keep an eye on the official website here:
https://www.sega.com/sonic-the-hedgehog/sonic-racing-crossworlds

You will find all the latest news and information on the Sonic Racing: CrossWorlds official website.

Best regards,

Amber"

There's still a chance for us to get Bomberman in there if we keep showing Sega Support via emails that we want our Bomberman in there!

I am calling upon the entire Bomberman community here to lend me their power for the sake of Bomberman being added to Crossworlds!

Ohhh that's interesting they specifically mentioned Bomberman. Also that they cannot confirm anything at the moment. Makes me wonder if there have been talks?

Always fun to speculate! Thanks for sharing.