Maybe the next time TOS is remastered for whatever video format comes next they'll add ridges to the Klingons and edit out the whole Klingon bit from Trials and Tribble-ations. Maybe make the Enterprise look more like the ST-09 one too. And make the crew look more like whoever is portraying them in the latest reboot in 2025.
Or, we can just accept Trek as it's been presented and not let the little inconsistencies lead us into retcon land. Aren't the stories more important than the little details anyway?