I completely agree.
Ambassadors should be people who know about crytpo and blockchain, who are interested in these subjects and the project so that they can represent the project with the necessary motivation.
Agree with rijaljun, brand Ambassador don't need to a celebrities. Some project more prefer if their ambassador have deep knowledge in blockchain technology and the project detail.
That's why the Ambassador usually is someone from their community that already join for certain period and follow the project development.