Nope and conspiracy theories can also be laid to rest on your second point too. I don't see the point in checking in to a service you don't use, however. But the system doesn't greatly care at this point, so long as you are HBO.

But if you have e-gate access and First Wing access then landside is normally faster and it's a more direct route than Flight Connections, unless CCR and using South Security (thereby losing "fast" track). But the computers couldn't care less.