No, the play store won't allow a second app with the same packageName
to be uploaded, an error will be thrown stating that packageName already exists
This applies to any google play store, if you uploaded the APP on private play store, you cannot upload it on the public play store and vice versa.
Now for the problem you are facing, you can use a workaround :
Set "appAutoUpdatePolicy": "NEVER"
in the policy so that the APP doesn't get automatically updated.
Push updates by specifying the minimumVersionCode
in the policy of the application and send it out to the devices or groups that you want the APP to be updated.
{
"packageName": "com.example",
"aliasName": "Silverline MDM Client",
"installType": "REQUIRED_FOR_SETUP",
"lockTaskAllowed": false,
"defaultPermissionPolicy": "DEFAULT",
"minimumVersionCode" : "36"
}