I use US bank, and their ATMs do give the option to choose whether you receive 20s or 100s.
edit: apparently headline was misleading and it wasn’t a US bank ATM, rather a US based bank’s ATM, but still, point remains, some ATMs do let you choose the bill.
NYT and WaPo both have articles about it. Paywalled, so I can see why OP wouldn’t link em. I can’t even get the wsj home page to load on firefox with ublock, so I can’t say whether they reported on it at all, but it’s not exactly like nobody is reporting on this.
I use US bank, and their ATMs do give the option to choose whether you receive 20s or 100s.
edit: apparently headline was misleading and it wasn’t a US bank ATM, rather a US based bank’s ATM, but still, point remains, some ATMs do let you choose the bill.