The docs warn that it can take hundreds of ms for a 32k crystal to startup.
I'm able to get the MS3V-T1R that shipped with the launchpad kit to consistently start in only 7ms. Should I be worried?
No. The key word there is "can" -- "can" doesn't imply that it "must" take hundreds of ms.
If that's important for your product and you want to sleep well at night, I would.