From Steve Dent at Engadget:
"With … advances in our technology, the classic adapter and app will no longer be supported after August 31, 2019," the company wrote in a blog post. "After that date, the first and second Gen adapters will no longer work." The company is now the owner of the latest $ 100 LTE adapter that comes with an optional Premium Premium $ 5 per month.
Seems like a pretty bold feature for a pretty niche product category. I own one automatically. I don't get much value out of it, and I certainly won't buy another unit from them.