Absolutely.
A submarine that's capable of only doing littoral operations by virtue of the fact it has a limited range could still perform a vital training function for task group operations on a global basis.
One of the things, though, that would be very challenging would be to send the submarine up into the Arctic. The distances that are involved even from Halifax, going up the east coast through the Davis Strait and into the Arctic, are significant. Basically, to take a submarine into the Arctic, you're going to need a range and endurance that a globally deployable system brings with it.