I know that some countries, like South Africa did not receive the HD versions of TOS for airing until 2014, so the HD masters may not reach all countries until 2020 for TNG. But apparently from just the international sales alone, TNG-R was a success. (
http://www.channel24.co.za/TV/News/Star-Trek-boldly-going-back-to-TV-20151103)
I don't see anything in that link that indicates that TNG-R's sales were a success. Star Trek, as a franchise, has tended to struggle overseas (at least when looking at the box office for the movies). I somehow doubt that international sales alone could cover the cost of TNG-R. Perhaps you meant to say that additional future revenue streams from overseas would guarantee that CBS profits from TNG-R?
Now, I personally hope that TNG-R was a success because, frankly, I loved the results and want everyone else to as well

. However, there are enough indications that TNG-R was selling less than CBS was hoping for, from Burnett's tweets to the Okudas encouraging people to buy the sets as they came out if they wanted DS9-R to... well, the current lack of DS9-R.
Of course, TNG's remastering wasn't cancelled midway, and CBS was asking around for quotes for the remastering of DS9 just a year or so ago, so it's not like TNG-R was a total disaster. At the same time, TNG-R cost over $20 million. I'm not sure how many Blu-ray sets and iTunes and Amazon purchases CBS needed to break even before relying on syndication and streaming services to start making a buck.
As for whether the Blu-ray sets are worth it? I guess it depends on how important picture quality is. The Blu-rays are beautiful (vastly superior to the DVD's), and it's like seeing TNG through new eyes. On the other hand, in the end, Data still gets the right to choose, the crew of the
Enterprise still save Picard from the Borg, Gowron still wins the Klingon Civil War, and Q still helps Picard and past, present, and future
Enterprise deal with that pesky anti-time anomaly. In the end, I got them all, but it really is a matter of taste.