dan meis is one of the best in this field. i know he designed the saitama super arena in japan, which is a concert arena and basketball arena which can change into a football stadium, from 20 thousand to 30 thousand capacity. The stand can mechanically move. The plumbing and everything in the stand automatically unplug and reconnect back in once the area has transformed. it's really cool, the design is based on a japanese bullet train as this arena is surrounded by trainline, and not so new, i went there over 10 years ago. stadiums which can transform for multipurpose are not such a pain in the ass as it may seem, for the best designers.
clearly the location and environment (water) and local architecture will be a big part in influencing how the stadium is designed in it's features and look. his roma stadium is based on the colosseum, the docks stadium will be unique too. just how these influences are put into the design is pretty exciting to find out. but for sure it won't be a replica of some existing stadium