Many reputable ebikes manufacturers certify their bikes for sale in Europe, through the CE mark and related EN certifications, so hopefully the FDNY will accept that as a comparable certification indicating quality.
Hopefully this prompts some battery alliances to form. Rather than everyone going out & certifying their own packs, there should be a couple standard form factors, that ebike makers pick from & use.
A year ago, Honda Kawasaki, Suzuki, and Yamaha teamed up for a motorcyle-scale battery effort, under a new company name Gachaco[1]. Their first effort seems to be based on the Honda Mobile Power Pack battery. That's a partial example. But just making a real standard, that anyone can use, still seems far off here. But now seems essential to keeping costs under control.