Adobe has just released Lightroom 6.14, the last update for Lightroom 6 users. Therefore, this blogpost is only relevant for those of you who are still on Lightroom 6. If you've already moved to Lightroom Classic CC (the subscription version of Lightroom, this message does not apply to you).
What's new in Lightroom 6.14
Lightroom 6.14 doesn't bring any new features. Only a couple of bug fixes and some new camera and lens support. Among the new cameras, the Sony Alpha 7RIII and the iPhone X are probably the most noteworthy.
What should I do when I buy a new camera in 2018?
Well, you have three options, basically. If you stick with Lightroom 6, you can use the free Adobe DNG converter, which will be able to convert your new camera's files to DNG files which you will subsequently be able to import into Lightroom 6.
The second option is to upgrade to Lightroom Classic CC, the subscription version of Lightroom. Not only will you have continuous camera support, but you'll also gain access to all the new features you have been missing out on for the last 2 years, since Lightroom 6 was introduced. You can find a comprehensive video review of all the features in these blog posts (English, Dutch).
Finally, your last option would be to leave the Lightroom ecosystem altogether and switch to one of the many competing applications, such as Capture One, On1 Photo Raw, Luminar and the like. Personally, I won't be making that switch any time soon, as the only true Lightroom alternative is Capture One in my opinion (because it has database functionality in addition to being a raw developer), and this application doesn't support the Fujifilm GFX. Maybe Capture One think it's too much of a threat for their Phase One Medium Format systems, which are three times as expensive. I personally don't.
How can I upgrade to Lightroom 6.14?
The best way to upgrade is to not use the Adobe Application Manager but to use the direct installer links you find here. This way, you won't accidentally install Lightroom Classic CC instead of the 6.14 update.