There was an Ewok battles WWF (World Wildlife Fund) promotion for iOS, one where iOS users got Phasma shards while Android users got Poe shards, a Samsung pack that gave out similar rewards to this one though if I recall correctly it was IG-86 shards rather than 88.
As well, when The Force Awakens came out, iOS users got Poe and Android users got Phasma.
Because they think it's cooler. The "regular Chewbacca" exists in-game as a NPC and does exactly the same things as the Clone Wars one (according to the spreadsheet).
"7. Chewbacca Chewbacca is one of the first starter characters players will find in Star Wars: Galaxy of Heroes, and we’ve specifically made him the Star Wars: The Clone Wars version by giving him a golden bowcaster"