There is no requirement to put a TN on the TN page about this - but I do see it fairly often and, as a transcriber, we don't want the reader to think they are OUR mistakes 🙂
Examples of TN's I've seen: "Errors found in print are transcribed as presented." "In print, there are several [many, some, whatever is appropriate] errors. The braille is an exact representation of the print." "Print errors are not corrected by the transcriber."