> any memories "re-surfacing" in therapy are in fact newly created,

You're saying that those memories are exactly the same as all the other memories.

Every time you "recall" something, you are not pulling up some file that is always the same. You are actively recreating the memory.

There's nothing "fun" or insightful about this, this mechanism has been known for a long time.

Obviously it's not unique to psychotherapy.

> may have been created

Most things that "may" have happened do not warrant absolute statements such as "that's not a thing" (which, incidentally, is a particularly empty statement in any context, since every thing is a thing)