Would sticking to such a plain format, without lives from outside an empty court building or government office, be boring? Perhaps - but people watch the news channel for an average of 7 minutes as it is anyway, so it would hardly do any harm.
Stop chasing the breaking news, unless it's huge. They could even fill quiet slots with a rolling text service from time to time if necessary.
But without covering breaking and developing news, a news channel loses a large part of its reason for existing in the first place. A service that just repeats the news of the day in feasible and inexpensive, of course, but who is going to watch it when so much news is now available online 24 hours a day? There's a reason why CNN got rid of its old Headline News channel, which consisted (more or less) of the same news lineup repeated every 30 minutes (1993 promo
HERE). No one watched it anymore once the Internet became universally available.
Also, keep in mind that the seven minute average doesn't mean that most people watch rolling news for seven minutes a day. Some don't watch it at all, while others may view it for an hour or two at a time. The latter wouldn't be well-served by a bare-bones service.
As for the idea of a rolling
text
service -- well that may have worked in 1976, but not in the interconnected world of 2016, in which even on-demand Teletext looks old-fashioned.