Total BS. Analog tape under the best circumstance is equivalent to 13 bit digital.
What most people decribe as an improved sound is just a gain difference. I had a Revox A77 for a decade. None of my tapes sounded better than the record. The end result is the Revox is long gone and all the tapes are in the trash. But, I still have all the records. I recorded them only because I did not want to take a turntable and records to collage.