the forum is the best mechanism for that.
Just post something in the forum. That's it's purpose. To get that notification out to forum members.
I did attempt this a number of months ago. The issue is without the API, I can't convert the URL into the album ID to get the embed working. You could try it in the iframely plugin. But a standalone one would require your users copy the album ID or track ID out of the embed code. Which isn't in keeping with the "just paste the URL" like all the other plugins.
The fact they no longer support the API would suggest to me they don't really care about sharing music. So probably wouldn't use them anyway.