I agree with the notion I'm super sorry to reply with such a short response, but now I'm intrigued: How is Empoleon Anthro?
I wouldn't even say Infernape is anthro. In my eyes, none of the Gen 4 starters seem anthro. You said we hadn't really seen anthro ones before then, but Combusken (Gen 3), to me, is far more anthro than Infernape!
Out of curiosity, which Pokémon do you consider to be anthro? For me, it's only Combusken, Delphox, Greninja, Incineroar, Cinderace, and Inteleon!
I consider Empoleon anthro because its features are hybridized heavily with an emperorm having a crown, swords, and a royal outfit. (Can't remember the name of the clothing, but its the white clothing Empoleon dons.)
The ones which I consider anthro are any starters which are hybridized with a human role: Infernape with son wukong, Empoleon with napoleon or an emperor, Serperior with european knight like The Rose of Versailles, Samurott with facial hair and as a samurai, Emboar with military general Zhang Fei and Zhu Bajie, Chesnaught with a paladin, Delphox with a mage, Greninja with a rogue, Decidueye with a bipedal archer, Incineroar with a heel masked wrestler, Primarina with the human qualities of a mermaid such as hair, Inteleon with a bipedal spy, Rillaboom with a rocker with a rocker's hairdo, and Cinderace with a soccer player.
Comparing something like Noctowl to Decidueye or Dewgong to Primarina might give insight to why my list is as extensive as it is.
Here's a page that discusses the Gen 5 starters having human roles incorporated into their designs.