I did what I should have done before posting...created a test user and assigned them a Supervisor license and indeed it decrements when they're created, so named not concurrent.
There are not 12 Supervisor Desktops listed on System Information in YSE, only 6. There are not 6 of anything else.
MiCC 8 converted your licenses to concurrent viz. gave you 3x times your agent licenses. However your SWA would have jumped cause you are also entitled to free bundled parts. If you opt out of that, you go back to named licensing. Opting out is ONLY available for upgrades. You also can't go back to named once you have switched, but you can go to bundles (concurrent) at a later stage
As for supervisor licenses - if you are referring to admin licenses then I'm not sure. I've seen this too where after upgrading those licenses are increased by a lot. It is not meant to increase since those are NOT covered by concurrency in my opinion (I stand corrected though)