Surely it can't be that expensive to put up a live stream behind a paywall.. or heck, just put up a free stream in countries where it's not being broadcast and start building an audience for the future. It's not surprising that the UFC has gotten so dominant when all these other orgs don't even try to gain an international audience (Bellator is the worst! Seriously, their attempts to get on tv over here are beyond embarrassing).
When the UFC was in between tv deals a couple of years ago in the UK they rented time on some random channel at the last minute to show the event for free. I'm not suggesting Rizin should go that far, but that's how you build trust and a good relationship with your fans, not this. Yes this event will sink or swim based on Japanese viewers, but if they want to compete with the UFC for the best fighters long term and to be a 'federation' for international orgs then they need international fans on board.