Let's go through your links:
1. Trump's understanding of how the Internet works manages to be both out of date and flawed; Bill Gates never had any sort of control over the Internet, and he's not even present in the modern computing industry anymore.
2. This link is "satirical" which is a word used to often today to get away with writing fake content. Trudeau has never said anything about shutting down the Internet, and the alleged "shutdown date" has come and gone (February 21st) and yet here I am, completely unaffected and never having dealt with any "shutdown".
3. Satellite Internet does not rely on any local infrastructure. Most Satellite companies already do not offer service to places such as Syria, nor have resellers. It's likely that much of their organization is accessing the Internet through smuggled portable terminals already.
Another consideration is that even if it was possible, it would restrict the flow of intelligence from the region, their enthusiasm for sharing videos and using Social Media provides a wealth of intelligence about their operations, as well as information from other sources providing information on events and even what they are doing internally to combat extremism. Both are valuable intelligence sources which would be remiss to remove.
A better approach to prevent foreign recruitment is not to deny information, but to educate. Religious extremism of any kind proliferates through ignorance, and while it wouldn't be impossible to completely eliminate, peers or colleagues of possible extremist convertees could be more responsive in recognizing dangerous individuals before they act.
