In the ever changing world of software, anything is theoretically possible. But Lightroom dropping NEF support, not very likely.
Although let’s keep in mind that the question is not really about dropping support for "NEF" or "CRW" or… because those are not a single blanket format. NEF is the filename extension given to a very long list of individual and different camera (and even old Nikon scanning software) formats. What this is about is whether the earliest specific
camera models get dropped. Just like Victoria says in her article:
Should I convert to DNG?
Some of Kodak’s early digital formats are already unsupported by Kodak themselves, so how long will it be before other formats start to go the same way? It may not be an issue at the moment, but do you want to have to keep checking your old file formats to make sure they’re still supported?
Of course this is not a short-term problem. Lightroom really is unlikely to drop support for the oldest Canon, Nikon, and Sony cameras any time soon. And they do, we’re probably going to get notice well in advance, plenty of time of convert to DNG if we want.
The following is my own speculation, but it could play out like this: Adobe starts deciding that the list of hundreds of supported cameras is getting too long, and cameras more than X years old are too large of a proportion of the download. (The Adobe Camera Raw installer is already over half a gigabyte; only 1/3 of that is the plug-in itself, all the rest is camera support). I would guess that they don't remove support completely, but would first take some camera support out of the core download (like the oldest NEF/CRW/ARW variants or least used other models) and make you download them on demand if you happen to own one of those models. Then later they could decide to drop support for some old cameras entirely, but it will be many years before that is likely.
To me, the option to convert to DNG is more Adobe promoting the DNG standard than adding any real benefit.
Well, they should promote DNG. If camera makers never implement DNG as a built-in save format out of camera, then all software companies must continue, in perpetuity, to reverse engineer the sensors of all cameras that are released, and over time the list of cameras to support grows from hundreds to thousands. This is an ongoing cost and time burden that is not equitable. A large company like Adobe has the resources to keep doing it, but the burden is proportionally higher on small software companies who maybe would like to apply raw support resources to something else. Although it is not so bad for software that gets raw support for new cameras from a source like macOS or open source raw decoder libraries instead of doing it themselves.
But thinking about it some more, even if cameras saved to DNG and simplified the lives of many software developers, Adobe would still choose to spend resources supporting new gear. Because Adobe also creates and provides camera raw profiles (e.g. Adobe Landscape, Camera Neutral…) tuned to each camera, and lens profiles, and DNG doesn’t remove the need to do that work.