Should Instrumentation Key (instead of Connecting String) of an App Insight still be used in App service?

[felixtsem5]

Web App with App Insight sample

Issue Details

I'm trying to look for a simple example to create a Web App with App Insights instrumentation. I found the above example, but I see that it is still using the Instrumentation Key. According to a Doc, it sounds like Microsoft is recommending the move to Connection Strings. Searching the full repo I see 44 files with the string APPINSIGHTS_INSTRUMENTATIONKEY. Just wondering I should go to the Connection String or stay with the Instrumentation Key.