AIFF is used widely in audio production software; for exporting uncompressed audio many application default to AIFF. It’s the most universally useful lossless format; WAV support is ubiquitous too but AIFF has better metadata. FLAC and ALAC are good alternatives today, but not on the same level of support yet. For example, for purposes of price differentiation, Pioneer reserves FLAC and ALAC support for their most expensive digital turntables.

If you’re writing a Python script that outputs an audio file, outputting to AIFF seems like a save bet. Then again I’m not sure how many people are actually using the module from the stdlib--but neither does the PEP’s author, it seems. His level of research was asking his friends on Twitter:

https://twitter.com/ChristianHeimes/status/11302577994753351...

Well, they don't remove AIFF tho, just the lib -- which presumably nobody uses...