Businesses are scared to lose access to data hosted at US entities, because this recently happened, so they have good reason to fear something like that.

AFAIK, the US has never done that with IP space, but if we did see evidence of that, then you'd see similar worries about that for sure. But I think most of us see it as pretty implausible to happen, since the consequences of such move would be huge, and would probably end the internet as we know it today.