Brett Wilson, CEO of video buy-side platform TubeMogul, said in an email statement to AdExchanger this development was an "unfortunate development [for advertisers] as they are now effectively prohibited from buying non-skippable video ads and from using data for targeting on YouTube."
He claimed the impact on TubeMogul is "immaterial, since less than 5% of total ad spend through our software in Q2 was directed to YouTube."
Third-party demand partners, of course, still have access to AdX's publisher marketplace, and can still buy TrueView ads through AdWords. Google enabled programmatic buying of TrueView formats in April - through its own technology, DoubleClick Bid Manager.
It's easy to see the importance certain video products have for Google.
TrueView supposedly makes up 85% of ads bought on YouTube; advertisers like its cost-per-view pricing and consumers like its skippability.
Meanwhile Google Partner Select and Google Preferred (a buying option for advertisers wanting the top 5% of YouTube video inventory) are both programs designed to help Google position itself as a premium buy for brands and agencies - and, some sources claim, increase sell-in for its own ad tech.
Google has reportedly reached out to software partners to assure them of their continued importance within the Google video ad ecosystem, despite these changes.
Google declined to comment beyond its blog post.