Why? Concretely, what would I be trying to allow in Japan? Don't they mostly communicate in Japanese anyway? The US has things like local government, schools, businesses, clubs, organizations, etc. Because the US is where we live. That makes it inconvenient to default block the US. Australia has what that is relevant to us? I don't see any .au in my browser history. Or .jp. Or .ca. There is some ac.uk, granted, but that could probably be kept to a small whitelist. I highly doubt anyone would notice for years if ever if I blocked Japan or Australia. It's a near certainty that no one would notice if I blocked all non-English parts of the web.
Are US organizations hosting in Canada for some reason? They probably wouldn't go further than that for latency reasons.
There's the separate problem of foreign companies having US points of presence, but assuming these laws expand, I'd imagine that would eventually lead to liability for services like cloudflare providing the endpoint/hosting on US soil.