That’s not quite accurate. Jesus said do not call unclean what I have called clean. Paul was reluctant to minister to the gentiles because the Jews considered them “unclean”.
Jesus used the message of eating something declared by Jewish law or tradition to hold less value than whatever HE declared to be clean.
Basically Jesus was saying in effect don’t treat the gentiles as unclean and to be avoided if I tell you to go minister to them.
Jesus was only using the example of the unclean food to state that whatever he says is the thing to be obeyed, not tradition.
I don’t believe that Jesus was declaring those items to be clean in general but whatever He specifically cleaned or sanctified is now clean despite it’s earlier condition.
There is a Good chance what you are explaining might be right, but you must know you are in the minority among Christians in your belief?
Otherwise how did a ham become the traditional Christmas feast food?
Without being able to (or wanting to) reveal the knowledge of bacteria, germs and viruses to ancient man, the best God could do was to basically ban certain types of foods and give specific instructions on how others were to be prepared.
It may sound silly... but I get the impression that God sort of operates under something similar to the “prime directive” from Star Trek for the most part. In that he is very careful not to interfere to much with our development.
That is the correct understanding.