[whpalmer4]

The (very) old behavior referred to in the quoted release note was that if a single action list was marked completed and was set to repeat, the newly created project would be a parallel project instead of a single action list.

I've been unable to find a version of OmniFocus (including 1.0.1) where the completed project has its repeat status altered by the act of completion. I very much doubt it was intentional, assuming there is a version out there which really behaves this way. In any case, if you want to duplicate a project, a much better way is to select the project, do Edit→Duplicate, bring up the inspector and uncheck the repeat. That way, you are relying only on intended behavior, not undocumented side effects (possibly accidental, at that).