The “Disable deadline randomization” setting in Configuration Manager applies to software updates1. When this setting is disabled (set to No), the clients use an activation delay of up to two hours to install required software updates. This randomization reduces the potential impact of clients in the collection installing updates in the deployment at the same time.
However, this setting does not apply to application deployments. So up to 2021, there isn’t a built-in feature in Configuration Manager to set deadline randomization specifically for application deployments. The deployment of applications in SCCM is typically controlled by the available and deadline times that you set during the deployment process.