How does the government ban an os? Can't is a strong word, but I don't see that happening. It's a Canadian based foundation, not a Chinese or Russian company where they could argue national security in the same way they did with Huawei or TikTok.
It's more likely a federal os-level age verification law gets passed and grapheneOS compromises or backs out out of the US market.
Probably are. I think it still think a federal age verification bill has low likelihood of passing, but I'd say that's more plausible than an outright ban on GrapheneOS