I am genuinely trying to understand the "security risk" argument for this move. At the risk of the internet classic "I have a friend..." I do have a retired Army Special Forces (Green Beret) friend who's former "co-workers" I've met do high profile executive protection and have described what their work looks like because it's obviously fascinating - that's where I got this general "security playbook" from. They literally adapt head of state, diplomat, etc active warzone-level security measures for their services.
It's been mentioned by guests on the Joe Rogan podcast that even at his level he's surrounded by former elite-level military security at all times. Comments like "Wow, when I got to the studio today I wasn't expecting there to be Navy SEALs everywhere".
I still believe, all things considered, that elonjet almost certainly has to be the most secure aspect of movement for Elon and his family.
Besides which, taking the "scenic route" while flying completely defeats the point of flying being the most direct way to get from point A to point B. Hence the front loading of the airport security model.
You do as little "in air" security as possible, because that crap is horrifyingly expensive because physics.
A missile defense system was announced for Gulfstream aircraft at a cost of about $3.5m[0], which for a ~$65m aircraft isn't really that expensive...
[0] - https://www.aerospaceonline.com/doc/farnborough-gulfstream-o...
If he flies random routes, that’s true, but I doubt he does. You could figure out where he flies regularly, move there, and prepare your ambush.
Having real-time data adds that you can tie it to your alarm clock, and better time your final preparations. You wouldn’t have to suspiciously camp out for hours at an airport, for example, getting tired and risking discovery.
Now, is that significant? Maybe, if he’s paranoid enough to put a lot of variation in his flight patterns, but I doubt it. Also, as you say, “Any sophisticated and determined actor who would be able to deploy such means could definitely get the location data with or without a Twitter bot.”