I don't think Natural Language was ever an identity factor of 5E. I say this because 5R now has a lot of Keyterms, capitalized and put into a Rules Glossary, referenced now throughout both the PHB and DMG and likely all adventures and other books to come. Natural Language, even in 5E, wasn't all that natural; it was more Keyterms disguised as natural language, because the writers would consistently need to use the same phrases in order to keep rules parity with other aspects of the game. For example, if you have to distinguish between "melee attack," "weapon attack," "melee attack with a weapon," then you don't have real natural language; you have lower-case sloppy keyterms.
That being said, 5R has, again, clearly moved away from that. For the better. Makes the game much easier to write for now.