That's wildly untrue. I don't know where you got that.
Here's the list of current Lego themes. A large amount of them are owned purely by LEGO (City, Ninjago, Nexo Knights, Minifigures, Modular Buildings, Creator, Classic, Elves, Friends, Boost, Technic, etc.), and a majority of them if you include themes like Architecture (which require the rights of building owners to make replicas), Ideas (which require the licencing of IP owners, most of whom are LEGO fans and customers), Unikitty (An IP created by LEGO, with Cartoon Network working with them on the show), Juniors, and Duplo.
Less than half of LEGO's current themes aren't at the least partially owned by LEGO.
Source? When has LEGO ever said they are done using CCBS?
Except you can't say it with confidence, and it's highly likely some sets will make use of CCBS pieces, like many other sets do.
So I've looked into this, and best I could find was rumors. At best, leaks, but not very well substantiated leaks. Nothing has been said officially by LEGO, which means, for the moment, we should take it that it isn't cancelled.
I honestly think you're blowing it out of proportion. Even if there won't be a dedicated line for CCBS, that doesn't mean in the slightest that the entire system is dead, especially since it's become an important component of System sets as well.
And I've always been a strong proponent of the fans taking things into their own hands. Again, even if CCBS were to be scrapped altogether, there's still billions of pieces in circulation, billions of combinations yet to be made. People make custom parts for the system all the time. So it's never really going to die. It's always going to be out there.
I also believe thinking in this way breeds this unhealthy mindset of "us" versus "them"; the CCBS fans and the System fans. It's all still LEGO, and I hate to think that a simple change in design and utility is dividing LEGO fans into arbitrary groups.