I wasn’t responding to you, but to other posters who took a more dogmatic line. I thought your OP was reasonable. I don’t know how Fr. Barron would address the apparent conflict between what he says and HG. As other posters have said, there’s clearly no problem with saying in general that the creation story shouldn’t be read as literal history, but Pius XII did single out this issue of monogenism. Whether Fr. Barron is denying monogenism, and whether this is within the bounds of orthodoxy, are legitimate questions you raised, and the truth seems to be that no one is quite sure at this point.
This is currently one of the big issues with regard to creation/evolution for both Catholics and evangelicals. Calvin College fired a couple of professors for saying that there wasn’t a literal first couple.
In the Catholic Church, I’m unaware of any disciplinary action against those who deny monogenism, but what’s “on the books” seems still to be HG’s affirmation of monogenism.
Usually in the past, when you have an encyclical that seems to say one thing and a trend in the Church toward saying something else, there is an eventual reconciliation explaining how the concern of the original encyclical can be met in the context of the new trend (or a renewed condemnation of the new trend, of course). Past examples would include issues of religious freedom, extra ecclesiam nulla salus, the reading of the Bible by laypeople, and Biblical inerrancy vs. historical criticism (especially with regard to the Mosaic authorship of the Pentateuch). Another place where the reconciliation, to my mind, still hasn’t happened but there are signs that it may be needed is the Council of Florence’s condemnation of the observance of Jewish rites even if they aren’t regarded as salvific. The “Hebrew Catholic” movement, which I believe quite explicitly practices these rites, has been if anything encouraged by the contemporary Church. I am certainly not aware of any condemnation.
Of course, the lack of condemnation may simply mean that the Church is not being strict in its discipline. And I recognize that that’s exactly what conservative Catholics (and yes, I think there are clearly such beings, contrary to what some will claim

) think on this and related matters. I know that there are some on this forum who even think, for instance, that Mosaic authorship of the Pentateuch is de fide.
In short, I can’t see that things are as clear-cut as some folks around here want them to be. That is one reason I’ve stayed Anglican so long–Anglicanism is much more comfortable with “gray areas.” But I know that’s really just an excuse. . . .
I think the bottom line is that you are under no obligation to agree with Fr. Barron, but given the lack of any disciplinary action against him by the Magisterium, and your general admiration for his work, you might want simply to keep an open mind on this and see how the Church’s understanding of this difficult issue develops in the years to come.
Edwin