In the very first Pokemon episode, Ash gets Pikachu because the three starters are gone but in the Kalos region when Serena is about to get her starter pokemon, a Froakie is there even though Ash already got Prof. Sycamore's Froakie.
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Anime Logic
In the very first Pokemon episode, Ash gets Pikachu because the three starters are gone but in the Kalos region when Serena is about to get her starter pokemon, a Froakie is there even though Ash already got Prof. Sycamore's Froakie.