lol. You're right. When they said they made 5e with changes, I understood them to mean they were making 5e without changes.
I remember being invited to a 5e game, and when I got there the DM was like "oh, there's flanking bonuses." I felt so sad that I was lied to, as he said it was 5e, not 5e with changes.
As for the quote where he "lied", he expressly said they ported the rules from the PHB. What did they port it to? As for them STARTING from the PHB, duh. How could they port the rules if they didn't start by reading and considering the rules? You ASSUMED they would build everything from the ground up, which they did NOT say they would do, even in that cute little color coded block of text you provided.
Thanks for proving my point, nearly every aspect of 5e that they've tried to implement, they've changed with their homebrew rules, i.e., they've paid "lip service" to 5th edition.
Swen is the one who said that they started by implementing the PHB, those are his words, his description of how they developed BG3, you can simp for him all you want, but that still won't change the fact, that those were his statements, and from what we have in Early Access, it is obvious, that they did not do what Swen stated. They've tacked on some 5E concepts onto DOS, and called it DnD.