[e1ven]

It's not necessary to include that clause. Many software packages don't.

When they talk about making a package GPLv2+, instead of GPLv2, I believe that's the distinction they're talking about.

[sigzero]

No, if the clause isn't in there then it doesn't apply. You can talk about anything you want.

[e1ven]

sigzero - We don't disagree ;)

I was referring to what the article was "talking about", with /their/ GPLv2+ terminology.

If you license it as GPLv2, it's GPLv2 only.