not sure why that one escaped, might have gotten an exemption, manual overhaul, or “something” when they scraped/updated it
as an example, subnautica below 0 still holds it’s 6€ “voucher” price on itad, but Subnautica don’t and is listed as lowest for 15 on epic(not counting the freebie) 
i know after a little while they changed it from an automatic price, to count as a coupon on ITAD, meaning it don’t default/auto add that price,
but why then all games didn’t get updated “equally” to reflect this i’ve no clue 
, nor even why the bothered to in the first place, guess they must have felt it was necessary, -but not warranting enough effort to make sure it was “reverted” for all apps 
but yea, itad/price matching sites has their flaws, many are for instance “broken”, like mentioned with @fraggles in regards to price increase vs discount with early access, or just other events
most easy one to mention is; back before 2016 when tons of games were common to get massive discounts, flash deals etc. So some prices still remain as rock bottom for those games, despite (likely) never going to see that match again, and as result don’t pop up unless you adjust the notify price threshold for such games yourself
^which is also why it’s not really something to be used as a “be all”/100% reliable tool when for a glance comparison and quick purchase. But more something for those that want a decent avg aggregate, or penny pinchers or those that just don’t want to get taken in by “fake”/mediocre discounts -like the current steam sale 