Once a course is "completed" and subsequently launched,
(a) will our LMS run the course in "preview" mode?
(b) will our LMS stop outputting the cmi.suspend_data value?
Answer: Launching completed courses in preview/review mode is NOT the default.
This most likely just boils down to the way your lms is constructing
the launch link. You need to check your code where you create the
launch link. I suspect you'll find logic like:
if complete
launchUrl = launchUrl + "&tracking=false"
As such, you have control over this code and can just remove this code so it always launches with the same url.