The rider's meeting is very basic here in the States. They go over the different flags, entering and exiting the track, crash procedures, pit speeds, vendors and maybe a raffle. None of them that I've gone to actually walk the track. A few staff riders may go out and rip on the track during the meeting so anything that isn't on the tarmac doesn't matter. It's basically, they paid to rent the track, this is not a race, you're not a pro, we've got your money so now we own you. haha
A lot of people here are missing the point. We all ride on the track, race and we all need an adequate crash zone.
Those sandbags are there temporary and IMHO, if they were brought up at any time throughout the day, I doubt the track org would halt any sessions and address to the folks at Laguna. T5 is supposed to be a very smooth crash zone but not if you put an object in that zone that'll get you some air.
15M is a stretch but keep in mind, those who live in NorCal know that here is a life flight policy available just in case. Air Lift costs was about 20K for a short 5 min trip from T Hill to Kaiser. Tack on the other medical costs and it starts to add up.