Funny, the government does not say that. https://www.cbp.gov/border-security/...s/preclearance

Do you have a government cite that says "Pre-clearance means the flight arrives as a domestic flight" or is this another "it's too complicated for the average person" or "I discuss this with my expert friends all the time" type of justification? There is a difference between a domestic flight and a pre-cleared flight. A pre-cleared flight still arrived from a foreign country. Immigration and Customs is done in the foreign country, but it would be impossible to say a flight from an international location is domestic.

All if which is beside the point. The OP asked about picking up bags, and your response was horribly misleading, as was pointed out by numerous other posters. You told the poster to go to the domestic baggage claim, which is on the other side of the airport.