I skimmed through the main thread for the feature [0] (which seems to be so long that it sometimes doesn't load completely), and I didn't see anything directly related to the topic. There was some discussion about importing foreign relation stats with the new functions instead of remote table samples, but that's a different thing
If we aren't exporting stats for foreign tables then that is an oversight, the intention always was to fetch all available statistics for all relations. I can't offhand think of where we even have the option to exclude them.