Provided the device has a good data connection and the Google Play server is not very busy,  Google Play support services on the device will retry downloading the missing mandatory apps automatically, though one can go into the Managed Google Play app on the device and manually start the download if he/she does not want to wait.   

As far as I know, there is currently no way to directly force re-install from the web-console.  As all managed app files are  downloaded from the Google Play server rather than from MobiControl server,  having such a UI (a button or whatever) on the web console does not help if either Googles server or the Google Play support services on the device is not ready/on-line.    Actually, my recent experience enrolling a few hundred Android Enterprise devices  for a governmental customer shows that as long as the connection is good, all mandatory apps can be pushed in one go.   If either the wireless or Google server condition is bad, those devices with missing mandatory apps due to excessive failed transmission retries will somehow get automatically pushed at a later time.