Yes but I'm trying to figure out how much of a challenge this is even though it's clear that open source Android cannot be taken away. Does this mean that China/Huawei simply has to get a few softwares made (like Huawei Playstore) or does this mean that all US apps are permanently illegal or impossible to use on Huawei phones? Does it mean it's impossible to use Google Chrome/Firefox legally and all Huawei phones can only use Baidu (which is OK is China but not likely in Europe), or can you still download them without upgrades like any phone can? I do not know what this means and would like to find out.
I don't think side-loading US apps on Huawei phones would be considered illegal. The the ban is true, what it'll means is that Huawei's phones will lose the Google Play certification and some apps such as Google Pay will not work properly. What the apps can do is to insert a mechanism that actively detects Huawei phones and stop running upon detection. There are ways to circumvent all of this through methods such as rooting but I don't know the legality in it. If the US really goes all the way into forcing its app developers to actively blocking Huawei's phones (which is insane), then that's equivalent to the formal declaration of a tech war. I think it'd reasonable for the Chinese government to force all Chinese apps to leave both the Google Play Store and Apple App Store. Keep in mind that Chinese apps are a huge source of revenue for both Google and Apple.