This already happened (probably many times over). I had success with the original mp3.com 17 years ago. They made certain business decisions that got major labels angry and various details not important, they shut down.

What matters is that tons of stuff disappeared. I learned that I can't trust these types of platforms because they are for-profit and may screw us all over or make stupid decisions. I also can't trust non-profit options if they aren't really stable. I trust Wikimedia to stick around, and archive.org and some others (although everyone should donate to keep them strong!), but other, I dunno.

Instead of fully embracing SoundCloud, I've basically stayed distrusting and my creative publishing actually suffered a lot (although my concerns are part of what led me into understanding free culture, free software, etc. and why I'm aware of Hacker News now etc)