Yes, most companies have approval processes. They might even be onerous approvals processes. Amazon expressly forbid me from participating in game jams with people who were not in my org.
Worked at microsoft for 2 years, there are the same policies. It was not contractual though. It's just that there were notes broadcasted saying that whenever you discussed with third parties, you should use microsoft tools if possible. Want to meet someone? Send a Bing Maps link, not Google Maps. Want to share a research? Send a Bing Link, not a Google search. etc.
As for the confidentiality clauses, I work in finance, and the rules on IP and personal projects are the same as what you describe.
Yahoo allowed tracing from 2007 till 2011.