Swampert, Blaziken and Sceptile Lego Set?

While flicking through the instructions for the Blastoise set, I noticed that one of the photos appears to be taken from the Hoenn starter selection screen. Is this a mistake or an Easter egg? And does it hint that LEGO might already have a Hoenn-themed set in development?

https://preview.redd.it/wigvc6emq7ng1.png?width=1518&format=png&auto=webp&s=2eadc13906a0f4d1b08adb06ba0307edfcab4a35