Call me a procrastinator, but we still haven't upgraded our VPP accounts yet to ASM. I'm a little worried from what I've read.
My organization has 4 different VPP accounts, all which come through different funding streams. They need to be migrated to ASM as separate locations from what I understand in order to move everything over properly, and to have them maintain independence from the other accounts. If my understanding is incorrect, please let me know.
My BIG question is, what about the ASSIGNED LICENSES for each of those VPP accounts that are currently being utilized in the MDM? Many of our assigned licenses are associated with both users & devices. Will I need to revoke and reassign everything??!? That sounds like a nightmare.
We recently migrated from VPP to ASM. We only had one account/location and did not have to revoke or reassign any licenses. My understanding is that if you want to transfer licenses from one location to another (or collapse your 4 locations into 1) the apps would need to be revoked/reassigned at that time.
About a week ago we got forced to transition our VPP account to ASM. Logged into VPP and it gave a message that, "Your account may no longer be used on this website. Use Apple School Manager instead." with a link to ASM.
I wasn't involved in the initial transition but the fallout appears to have been a mish-mash of license misalignment. One of them was considered a legacy VPP account with licenses attached that had to be transferred to the other VPP account. Self Service stopped working, iPads couldn't enroll, a variety of issues resulted.
Basically the licenses that were assigned couldn't be transferred, so we had to go edit all 1,162 apps and change their VPP account. Then go into ASM and transfer the licenses to the main location. Certain apps such as Self Service has the 10,000 existing assigned licenses still assigned and couldn't be transferred until that happened - so new devices couldn't get a free license until those steps were completed (change app VPP account and transfer subsequently freed up licenses in ASM). We then had to track down the stragglers - there were a handful of paid apps that got stuck or didn't see the current VPP account to assign them. We had to uncheck the VPP assignment box in the app and wait - almost none of this was immediate, lots of wait time.
eBooks don't appear to want to revoke licenses, so those may stay. We're going to go confirm with Support on that point, but otherwise I think we're back up and running after that whole mess.
Those are the steps from memory.
Again reach out to Apple support and they will help you with the process.
Hope this helps.