Lifetime actually means lifetime. Of course if the lifetime of your trans ends up being 150,000 miles......
The only reason you should ever have to crack one of these is in the event of a leak or failure. Aftermarket shops LOVE to sell stuff you may or may not really need. So the question is, is there a concern with your transmission as it sits? Sometimes you end up taking something that isn't broken in the first place and fixing it until it is.