Your timing is wrong here, which breaks your calculations. I read some other articles that said FanDuel got $75 million in 2014 and $275 million in 2015, and then they sold in 2018, so not sure where you're getting your "9 years" from.
The claim that the valuation was artificially deflated due to conflict of interest seems stronger than the concern about liquidation preferences. FanDuel's 10x valuation growth from 2015-2020 backs up the charge of deflation.
https://www.wsj.com/articles/fanduel-founders-former-employe...