But if everybody tacitly understands that Scotty speaks about the limitations of the enemy when invisible, why would the discussion fail to cover whether the enemy will stay invisible?
I think I finally got it, sorry if you felt misunderstood last year.
I see your point, for a tactical briefing Scotty only looks at the current "picture" of a cloaked ship. It's a little too much assuming on his / their part, that the ship will do everything to stay cloaked.
Other than that I'd like to shift your attention on that strange "show & share" scene in the briefing room where Spock illustrates the Romulans' weapon power by smashing a piece of cast rodinium from the outpost's outer protective shield...why did they stop for the outpost collecting samples?
Or did they actually stop by to recover some kind of unmentioned flight recorder that contained plenty of information on the Romulan ship?
Although the Earth outposts had monitoring equipment, it apparently had limited visual range, so that the Romulan ship warped there close enough and then went invisible once coming into that range for its stealth attack.
But if you think this through these outpost guys had a shitty job. In case a Romulan invasion fleet ever came into their visual range, all these guys could do was to alert Starfleet before being killed by such an invasion fleet.
It's also somewhat strange that Hansen had been "alerted" by one of the other outposts, but didn't send out a distress signal before he himself was being attacked.