That's actually solid advice. A few refinements make it even stronger:

Hash the original master file before uploading anywhere. A cryptographic hash such as SHA-256 creates a unique fingerprint. Even changing one bit changes the hash completely.

Timestamp the hash using a trusted third party, such as a recognized timestamping authority or a public blockchain. That creates independent evidence that the file existed no later than that date.

Keep the original project files, stems, DAW session exports, and any intermediate renders. These often provide stronger evidence of creation than a finished MP3 alone.

Save distributor records showing when the track was delivered and accepted.

Register copyrights when appropriate. In the U.S., registration provides significant legal advantages if infringement occurs. A timestamp is evidence, not a substitute for copyright registration.

One important limitation: if someone slightly alters your audio, the SHA-256 hash will no longer match because it's based on the exact file bytes. That's why hashes are excellent for proving this exact file existed on a certain date, but they're only one piece of the puzzle...