Re: Update the outfit for next solo film
No explanation for a costume change is needed imo; I happen to think that the audience goes into these things expecting some sort of natural evolution/progression in many aspects of the characters life in the duration of time lapsed since we saw him last. An improved and enhanced costume would just be one of those things.
Chiwetel Ejiofor for Black Panther.
Matthew McConaughey for Lex Luthor :( Oh well.