I don't keep a list of all streaming services and all available APIs, so I can't answer to that question. All I know is that it is still perfectly usable with the services relevant to me, and I see no need to replace it.Does your Linn need updates to keep up with streaming services' APIs? Does it support all of them?
Another thing is that music service APIs are not really that complicated. As long as Linn stays in business of making streamers and developing API support required by the markets, making the support bit backward compatible is generally speaking not a huge effort in this particular case.