Buddism has always adopt in order to stay relevant. There are many ways to achieve enlightenment. Maybe US Buddhists will find their own unique path forward.
There was a great saying by Ajahn Chah, who always seems to be quotable. He said "How come everyone says Buddhism is old-fashioned and needs to be adapted? No-one ever accuses the defilements as being old-fashioned and outdated; no, they're always up-to-date."