Not withstanding Wikipedia's weaknesses as a source in general. There are a couple of problems with that definition.

The idea of the strip was to differentiate the carpet joints outside of Vegas from the established downtown properties. Until the Stratosphere, the "strip" properties were all outside of Las Vegas city limits.

As I understand it, the City had the opportunity, at one time, to annex the strip, and failed to do so.

Also if we are going to include the airport then their are other properties which are "on the strip"

I think the Wikipedia definition is off in at least the way it presents the info. At least in part.