I agree with you, but would phrase it differently.
You want some indication that any leak of your current password actually hasn't been mitigated. A failure message that your password hasn't actually changed (due to being identical) is functionally the same as allowing the password change and giving a warning that the passwords were identical (modulo some back-end details like if the password salt has changed and if the password change date has been updated).
You want some indication that any leak of your current password actually hasn't been mitigated. A failure message that your password hasn't actually changed (due to being identical) is functionally the same as allowing the password change and giving a warning that the passwords were identical (modulo some back-end details like if the password salt has changed and if the password change date has been updated).