>>10530442>>10532001>>10533481From what I noticed, the way these so called "exclusive rights" in Japan seems to work is sponsorship for the TV show. Bandai is a big company that supports many TV shows as the primary sponsor (for a Toy company) like Kamen Riders, Ultrraman, and some anime series. OP, DB (back then) fall into that category. Big sponsor like that get to make the toys and the license holders will not let other companies get involved in fear of losing all that sponsor money next year, next show, etc. Unless the market is very different, like soft vinyl kits.
When big name IP ventures outside of the sponsored media, it's the best opportunity for Toy companies to bypass the main sponsor. For OP liver action Netflix is obviously spomsoring the show, meaning no Bandai money, thus toy companies can negotiate. We saw this happening with the ULTRAMAN manga turned anime, the mech suit one. Or the Shin Ultraman and Kamen Rider films had other toy companies make products.