With the release of LR6 (nay LR CC) it is becoming clear that it is only a matter of time before standalone Lightroom is put to sleep for good.
Maybe, maybe not. I don't see why it matters.
Aperture was standalone licensing, and it didn't stop Apple from shutting down development. Standalone licensing is clearly an insufficient hedge against future abandonment.
The chances that Adobe will shut down its activation servers, out of the blue, with no notice, and crippling tens of thousands of working professionals, is very slim. Even if they were going out of business, users will have more than enough time to migrate data to a competing product.
So I am thinking why spend any more time on Lightroom.
That's your choice.
That said... Your reaction doesn't sound particularly rational. If you can migrate your catalogs to another program with minimal loss of data and minimal downtime, why do you need to change because you're merely worried that you'll have to migrate your catalogs at some later date? Will it take less time to do it now, than at some future date which may never arrive?
Any piece of software that your workflow or entire business relies on could be abandoned by its developer at any time. Are you going to change your process every 6 months, to ward off that mere possibility?
If it is a dead-end product, it might be worth spending money on another company's product which at least has a commitment to on-going support of their product.
Lightroom isn't a "dead-end product." It's got just as long a future as any other catalog/RAW developer app.
Rather than panicking about things that might never happen, I'd suggest you figure out what tools work for you, and don't worry about the future.