From these two articles, I offer the following info about SEC revenues that may help understand the impact of the SEC Network.
https://www.cbssports.com/college-footba...c-network/
https://www.usatoday.com/story/sports/nc.../97400990/
2013-14 (Pre-SECN, Pre-CFP)
TV/Radio Rights: $210.4 million
Postseason Revenue: $98.6 million
2014-15 (SECN Y1, CFP Y1)
TV/Radio Rights: $311.8 million
Postseason Revenue: $162.8 million
2015-16 (SECN Y2, CFP Y2)
TV/Radio Rights: $420.0 million
Postseason Revenue: $180.6 million
Basically, since the launch of the SEC Network, its television rights have increased by about $210 million/year. Although they probably also got a jump for the addition of TAMU and Mizzou, its Tier 1 contract with CBS did not change at all, so the vast majority of the increase can be assumed to be from the SECN. This appears consistent with an assumption that the SEC is getting around 50% of the profits of the SECN, which are between $310 and $345 million.
The reports distinguish TV revenues from Postseason revenues, and show a huge increase of over $80 million per year between 2013-14 and 2015-16. This would appear to be CFP related. Thus, it is reasonable to assume that the increase in TV revenues is unrelated to the CFP.