Not a rumor
CCG have augered in, according to my friend who owns a hobby store. I used to own one too, so we talk shop. M:TG and Pokemon are still being sold, but at drastically reduced numbers. M:TG, we agree, was over expanded and ruined because they were too greedy. Pokemon was a fad, like bottle caps and pet rocks etc., and anyone with half a brain should have known that it would end before too long. (Hasbro, and WotC did not know that, they overhired based on Pokemon, and have been gutting WotC to make up for it.)
D20 stuff is still selling, but some of the modules aren't (AEG and so on). The core book sales have tapered off to smaller, more normal numbers now.
What I think it means is that there will be even lower levels of customer response, such as errata, and more concentration on potential high sellers. Due to the lead times, WotC has a lot in the pipeline, but after that starts clearing, I don't know if they have the staff in house to make any new things worth buying. I don't think WotC can exist only selling core books. Remember the old 2nd edition days when they would publish as many guidebooks as possible, for no reason other than to keep the dough rolling in. But that didn't work.
I expect Hasbro, which has no clue about this industry, to eventually sell off WotC after they have milked it for what they could, probably whenever the sales reach a certain minimum threshold. It is even possible that they will agree to sell it to interested parties, who will use debt to finance it, leaving WotC finally unfettered, but devoid of resources and capital. This process is called capitalism, by the way, and is how businesses have behaved for 100 years or more.