Not sure about Monza, but Nordschleife being long I guess it would be a nightmare to laser scan and model (I guess they could do 2 other tracks at least in the same time, which most probably would be better for the cash flow, and I am saying this without any criticism).
Monaco is only a temporary track, I think it would be a challange to do the scanning while it is open for public traffic and even more when it is a race week end.
The Ring is 4 times as long as Spa. They could do it, but it would take quite a while. Even if they get past the licensing, it might cannibalize some of the daily revenue they get to shut down the track. Since, it might require 3 weeks of "no rain" open track time, it would be a logistics struggle. They could shut down parts of the track only, but again, that's more logistics problems.
So, the issues are...
1. Licensing.
2. 3 weeks of "no rain" days to scan.
3. Lost revenue added to cost for shutting down the track.
Not sure if the Ring charges every day, or only certain days etc, but likely some of the scan days would cost them lost revenue at $20 a car or so. If they allow a car every 10 seconds, that's 6 cars a minute or 360 cars an hour at $20... That might be $6,600 per hour of $50,000 every 8 hours. Over 3 weeks, that would be a lot of lost revenue added to the cost even if they only charged on weekends.
It could be done, but working around the "pay to drive" days, local traffic, rain days etc and it's a logistics nightmare compared to many other tracks.
Spa will take at least a week to scan. The Ring is 3 times as long... It's not like they don't want to scan it.