Xbox has said there are currently no plans to develop titles specifically for Project xCloud.
A company spokesperson told Gamasutra that plans for the service are focused on streaming games from its consoles, rather than building ones that are entirely dependent on the cloud.
"We're very early in the multi-year journey for Project xCloud, which is currently in public preview," the spokesperson said.
"We are investigating a variety of new capabilities made possible by the cloud. However, we remain committed to an approach with game streaming that is complementary to console and have no plans for cloud-exclusive content at this time."
The suggestion of Project xCloud exclusives originated from an Stevivor interview with the service's corporate vice president Kareem Choudhry, who said Xbox was in "early talks with first- and third- parties" about cloud-only titles, although he stressed there was nothing to announce at this time.
As mentioned, Project xCloud is currently in public preview. At X019 in London earlier this month, the platform holder it was expanding the preview from four titles to more than 50 with plans to bring the service to new markets in 2020, including India, Japan and Canada.
Microsoft's main rival in the streaming space, Google Stadia, launched last week with one exclusives. When the internet giant announced the service earlier this year, it also announced a new studio that would be developing games that are only possible when powered by the cloud.
However, only one exclusive title has launched so far: Gylt, a spooky adventure by Tequilla Works.
We spoke to Stadia Games & Entertainment boss Jade Raymond last month about the "spectrum of bets" Google is making on Stadia.
Critics were largely disappointed with Stadia in its launch form, as you can read in our latest Critical Consensus.