From what I understand, it's the opposite.
The television networks don't give a shit about how many people are in the stands. We have a couple of decades' worth of evidence with various bowl games to demonstrate that. If "butts in seats" were a metric of the financial viability of a college-football game, then things like the Hawai'i Bowl and the Bermuda Bowl would've been out the window a long time ago. Shit--the Hawai'i Bowl is being played this year in a stadium with a 17,000-seat capacity, and it'd be a miracle if that game sold out.
The ratings on conference championship games indicates that, if anything, they'll expand. The Big 12 instituted a superfluous championship game back when it was a 10-team league precisely because its television partner demanded it. Has anything changed?
Someone--maybe Joel Klatt, but I can't remember--laid down a purportedly highly informed opinion that Championship Saturday was going to expand in the next two years alongside an expansion in the CFP. According to whoever, the CFP is going to expand to 14 teams with the SEC and B1G being guaranteed four spots and their champions guaranteed the two byes. Those four spots will be allocated to the winner and loser of the conference championship game and then to the winners of two play-in games.
So if that were the deal this year, you'd have a Saturday football schedule for the SEC that looked like this:
11:00 AM: Play-In Game (6) Alabama @ (3) Tennessee
3:00 PM: Play-In Game (5) Ole Miss @ (4) South Carolina
7:00 PM: Championship Game (2) Georgia @ (1) Texas (in Atlanta)
I don't know how likely that is to happen. But understanding the networks' insatiable appetite for college-football content, I'd say it's significantly more likely to happen than getting rid of conference championship games altogether.