If this is true, i will cancel my subscription. I'm using tailscale and certainly won't use a service that wants to dictate me how to use my device.

Just cancel it.

Soundcloud these days is nothing but a spambot filled website that have ripped countless users’ tracks and scam to earn fake followers, which the platform doesn’t block these bot but instead shallow banning proper users. The support is also nonexistent and my support ticket hasn’t being been responded for more than an year.

I ended up trashed my account because I got shadow banned for no reason while they keep on stripping off basic features. Some of the users in my community also faced the similar stories.

Unless there is an irreplaceable feature in SoundCloud you rely on, I see no reason to use it.

If you're using tailscale it's a true VPN, not a proxy, and it won't have any impact on you. If you're using the Mullvad add-on that's a different situation.