R2-D2 is, explicitly, the exception to the snapshot rule.
He's special, and you know full well why. He's not someone to point to when petitioning non-snapshot tags on other characters. Otherwise, every Han would have to have the Empire and Imperial Trooper tags now.
Also, yes. Yes, Kanan and Ezra both really were Jedi. Kanan every bit as much as Hermit Yoda and Old Ben. Kanan was even knighted and recognized by Yoda as such during the series, and Ezra was the padawan to a Jedi knight, again recognized by Yoda.