Well it’s likely the adoption by the Latinx. I think that demo grows as you move west. In Texas it’s become more common in that demo and the redneck whites. The monied still have it but more commonly go towards super preppy names like Tripp, Shep, Archer, Preston. A common theme I see if you dig deeper is they name one of the boys the mom’s maiden surname. But in general, surnames as first names is very common in this demo. I mostly exist in this demo of WASPs and my wife has I think 4+ cousins named in the mom maiden name format, I didn’t realize it was a bigger thing until we had kids and learned a lot of our friends had also done this (I thought maybe just unique to my wife’s family, but bigger trend). My family wasn’t monied so I wasn’t really exposed to it until adulthood.

Sorry to bring up race but it’s the US and the SES is too highly correlated to ignore these in a data conversation and we all do things slightly differently roughly by race/background, there’s no monoculture in the US