Is Sys.Application.notifyScriptLoaded still needed in a desi

According to the Microsoft Ajax Sys.Application API documentation (http://msdn.microsoft.com/en-us/library/bb310952(v=vs.100).aspx), the following method call snippet which I commonly see at the end of designer template js files is now obsolete, and no longer needed in the current version of the Microsoft Ajax API library. Do we need to continue to use it in Sitefinity 5.x?

example code:

if (typeof(Sys) !== 'undefined') Sys.Application.notifyScriptLoaded();