I'm not sure we have the confidence to run the logic that way right now. There are still some ways to harmonize "this hit China really hard" and "this won't impact much of the rest of the world" at this point. I've seen it hypothesized since before it even spread out of China that this may happen to target some people more than others based on different levels that people express the receptor that this virus targets. There's also some reason to wonder if China is getting hammered due to widespread smoking [1], and even more widespread exposure to pollution levels that are not entirely dissimilar to smoking. If, perchance, all of these factors are true at once, then it could be that what was in China was a perfect storm for them, and it'll be just a cold for everybody else.
We still don't really have the evidence in yet to know. At the moment we can fit the facts both to "everyone's in big trouble" and "it isn't that big a deal anywhere else". In some ways, the best possible news would be that it's been spreading in the US for weeks... and we didn't notice, because it's literally not noticeable because it's not that big a deal here. I'm not pitching that as "truth" at the moment, but it's on the table.
[1]: https://www.preprints.org/manuscript/202002.0051/v1 - note this preprint disagrees with the "differential expression" theory; given it's "early days" I'm taking this merely as a data point, not proof yet. This could explain how it's a catastrophe in a high-pollution city and just "a cold" everywhere else. This scenario raises the interesting possibility that covid-19 could have started anywhere, and it simply wasn't noticed until it happened to get to Wuhan through normal mechanisms. What if "patient 0" turns out to be an asymptomatic business traveler from $NOT_CHINA? I'll call this a low-probability outcome, but what if we start widespread testing in the US only to discover that almost everyone already has it?