i accidentaly release a device from ABM. Can it be readded

Yes. You have two possible options.

Option 1: Contact your reseller. Contact the people who sold you the device and ask that they resubmit the device to your ABM. Provide them with the serial number. This is possible as we do it all the time. Remember, your reseller is a link in the chain of custody created when purchasing devices through the DEP program. (Apple > reseller > customer).

Option 2: If your reseller is unwilling (or incapable), you can use Apple Configurator (available for free on Mac and iOS) to sideload the device. Ah, but the device will need to be erased in order to perform this action. Using Configurator on an iPhone offers more capabilities as you can auto-assign the asset to a specific MDM (saving a step). If you use the Mac version, the device will appear in ABM as managed by "Apple Configurator." In the case, you simply reassign to your Intune MDM, wait a few minutes (or in the case of Intune... 24 hours - yuck), and you are off and running.

Just a tip, if you are allowing release from your MDM and you are still in testing, you may want to disable that feature. You may inadvertently release assets that you are simply trying to delete from the MDM.

Log into ABM. Go to preferences. Select your Intune MDM from the "Your MDM Servers" list. Hit the Edit button.

You likely should uncheck the "Allow this MDM Server to release devices." This will save you from accidentally releasing the asset during iterative enrollment testing.

Press Done. And while I don't think you really need to do it, I've gotten into the habit of exporting the server token and updating it in the MDM.

Good luck. Hope this helps.