Does ‘Fiducia supplicans’ affirm heresy?

The Vatican argues that the declaration does not change the Church’s teaching on marriage and sexuality or state anything heretical. But there are Catholic practices that cannot be altered without rejecting Catholic doctrine. The assertion that Fiducia supplicans blesses only irregular couples and not their unions is functionally false. To bless such couples is to confirm them in their sin and encourage their alienation from God.