You are correct.
Think about it as Service Types for Future Listings.
Though you can create a favorites list and assign the Racing Officials and Racing Teams Services Types to your created favorites lists.
Actually the RR Wiki has a somewhat updated list of NASCAR (and other related)
racing frequencies: NASCAR - The RadioReference Wiki
Granted they are not in the RR database but with a tiny bit of cutting and pasting into
Sentinel a decent Favorites list could be made up in a hurry.
Though I do agree most of the officials are using MOTOTRBO, most of the racing teams
themselves appear to still be using regular analog comms.
Thanks for the feedback, guys. Much appreciated. The team's frequencies are all over the net, and it'll be trivial to create a Favorite list in Sentinel when and if I get the chance to go to any races this year. I just wanted to make sure they weren't grayed out due to something dumb I'd done.
It looks like they're placeholders of sorts, for something that may be coming. I can already picture little car # icons where the Service Type icons normally appear.