Hi,
Correct - You can have one account with up to 10,000 APs today and an unlimited number of switches. MSPs can have an unlimited number of accounts with up to 10,000 APs each.
Each AP and/or switch requires its own individual subscription, that way they are all automatically provisioned in your environment when you first connect and as you add devices. No need to enter serial numbers, MAC addresses, etc... to get a device added to your account.
Best,
Thomas.