Yes, the tern "linear" refers to a broadcast on traditional television.
If this is an Apple driven deal, I would assume they would have a similar model as they have with MLS. They'll have all games exclusively and they'll have a television partner who will simulcast one or two games a week. If they do this, the partner will not be anyone with their own streaming service, so the most likely linear partner with this model are the Fox networks or the CW. If it is the Pac 12 Network that's only because they can't find another partner. Pac 12 Network should be relegated to essentially 3rd tier rights and reruns.