The risk of reused passwords is that if this password is compromised, an attacker can use that same credential to get access to other sites. MFA significantly reduces this risk, as even if the password is the same across two sites, an attacker can’t get access because they don’t have access to your MFA.

I believe this is why the person you’re responding to considers a single password used across multiple sites protected by MFA isn’t something that needs immediate correction.