Of course, they are assuming they can do another TV series. Make it part of the Universal tour. Promo it on Peacock etc..
But, yeah, $400M is a pretty steep price
And, that's why buying this Franchise's rights for $400M is so questionable. It only buys the rights to this storyline and characters.
ANYBODY can and will make "an" Exorcist story. They just can't make "this" Exorcist story.
And, that's not even mentioning that the Franchise hasn't had a...