You don't necessarily need mirrors when you have reliable (probably ASIL-B, maybe ASIL-D) cameras systems that recreate that view inside the vehicle, although I'm not that well versed with European laws.

They could also just add mirrors as has long been standard between concept and production motorcycles. (Example [0][1])

[0] https://2yrh403fk8vd1hz9ro2n46dd-wpengine.netdna-ssl.com/wp-... [1] https://i2.wp.com/www.asphaltandrubber.com/wp-content/upload...