Welcome @John_Bauer!
De novo creation is important because it is the stated reason that many people in the Church are troubled by evolution, or even outright reject it.
See, for example, this TGC video: Keller on Adam and Eve.
See, also, Wayne Gruden’s objections to evolution: 12 Ideas You Must Embrace to Affirm Theistic Evolution | Crossway Articles.
See, also, Ken Keathley’s statements about the creation of Eve (echoing Kidner), Southern Baptist Voices: Expressing Our Concerns - BioLogos.
See my analysis here, BioLogos and the Crossway TE Book.
So we have several scholars from several traditions in the Church all pointing to de novo creation of Adam and/or Eve as important to them, and the reason they are troubled by evolution. All these scholars are informed. They have heard the theological and hermeneutical arguments against de novo creation and were not convinced.
Here is how evolutionary creationists responded:
“evolutionary creationists cannot affirm the traditional de novo view of human origins”
https://biologos.org/articles/a-flawed-mirror-a-response-to-the-book-theistic-evolution
In contrast to this, here is how I responded to Gruden, Keathley, and Keller,
Grudem is correct; theistic evolutionists have not been sensitive to the theological concerns presented here… All too often, evolutionary science is incorrectly understood to overturn the traditional theology of Adam. Certainly, evolutionary science allows for no-Adam theology, but it also allows for historical Adam theology too… This year, also, there was a surprising advance in our understanding of how evolutionary science interacts with theology (e.g., S. Joshua Swamidass, “The Overlooked Science of Genealogical Ancestry,” Perspectives on Science and Christian Faith 70 [2018]: 19–35). We find that Adam and Eve could be genealogical ancestors of us all, less than 10,000 years ago in the Middle East, de novo created, without parents. As surprising as this may sound, these confessions are entirely consistent with evolutionary science. With this correction in mind, it is not clear if any of the theological claims Grudem lays out are in conflict with evolutionary science.
Theistic Evolution: A Scientific, Philosophical and Theological Critique - The Gospel Coalition
That is why it is important. Several scholars say de novo creation is important. For 160 years, they have been incorrectly told that these beliefs were in conflict with the evidence. Maybe they now have less reason to reject evolution if we make space for them.