I can't see any argument for the idea that existing words limit our imagination. Words do not "contain" our knowledge of the things they reference. They only reference it. They point at it so others can find their way to it. If it's complicated information, the words become specific enough to make the critical distinctions that need to be made, or else the words wouldn't be useable. But they don't contain anything more than those distinctions.
To be very clear:
- Words only contain enough information to make the distinctions that need to be made among things
- Words do not contain any more information than that, and certainly not all that is known about .. whatever
- Thus, words offer no limitation to thought or imagination