Heresy is an obstinate post-baptism denail of some article of faith. Our policy is give people the benefit of the doubt. This is not new teaching. Here’s a catechism entry from 1876:
Q. Do Catholics charge all that are apparently out of their communion with the crimes of heresy and schism, and consequently exclude them from salvation
A. All those sincere people belong to the soul of the Church, who, being baptized, and believing the great fundamental truths of Christianity, and who are prevented from believing it in all its details, not by carelessness, nor temporal interest, nor human respect, nor the spirit of obstinacy, nor by malice, but simply because they never doubted, and never had sufficient means of knowing the truth, which they would embrace at once, and with gladness, could they only discover it,*—*all these, we say, belong to the soul of the Church, and will be saved, if they lead good lives and do not violate God’s law.