The trailer just says 2022.It feels like it if it was definitely 2022, Nintendo would have said "2022" instead of "aiming for 2022"
They said "aiming for 2022" because that's what they're doing. "Planned for 2022" or "intended for 2022" would be synonyms. It doesn't mean, like, "we want to prepare y'all because we kinda don't think we're going to hit it!"
People are reading waaaay too much into that one word. They announced BotW2 for 2022. It's as "definitely 2022" as any other game — meaning delays are of course possible, but we shouldn't act like they're probable just because someone said "aiming"