I think there is a middle ground there where the Lizardfolk entry includes statblocks for Lizardfolk Hunter, lizardfolk Champion, Lizardfolk Lurker (a elemental water variant) and lizardfolk geomancer (a elemental earth variant).If people really need a standard Orc or Lizardman statblock for their games... you can always just use your 5E14 Monster Manual statblock. No one is going to care that you used a product outside of the 5E24 books.
Or if you don't want your Lizardman Geomancer to be classified under the 'elemental' umbrella so that your player can cast Hold Person on it... then you can just take the category off. No one is going to care that you do that.
In other words, adding depth to the group not only makes them more useful overall (having different roles and CRs) but also shows GMs what is possible.