It would probably be a good idea to call your local police department’s non-emergency line and report what happened. And that your son didn’t mean to do it.
I’ve tested the phone sleeves and they appear to work for mobile connections – I didn’t receive my test SMS messages until I took them out of the sleeves. I don’t think they work with 5GHz Wi-Fi since it appeared that they were still connected to my router.
I’m sure it will have no negative impact on the efficacy of the bag but I am not sure that the packaging of the sachet is designed for long term use in a bag that is carried around and joggled around and contains electronic equipment.
The sachet is also a choking hazard. So if in an environment where pets or small children might get hold of it, best to throw it out.
Armed with those caveats, yep, you could leave it there - but really the main goal should be to store the bag where it gets good air flow.
Technically, silica gel, not silicone, I would suppose.