We could have come up with {ghojmoH} without Okrand giving it to us, and we could justify using it in our speech and writing to mean “teach", but then he could have later given us a different verb for “teach” that wasn’t derived from {ghoj}. By giving us an explicit {ghojmoH} to mean “teach”, he was informing us that we could freely use {ghojmoH} without waiting for some other verb.

Well, no. He didn't include ghojmoH to give us permission to use it. He included it because he knew that people looking up words on the English–Klingon side might look for a word like teach, and if he only included root Klingon words they wouldn't find it. As a convenience to the reader, he added English words that didn't have root Klingon equivalents and gave their constructions in Klingon.

This has the added side-effect of giving us canonical glosses of productive Klingon suffix use, but "canon" wasn't a thought in Okrand's mind when he wrote the dictionary.

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SuStel
http://trimboli.name