When Game Freak decided it was time to turn Pokémon into a collectathon that not only involved creatures, but human hairstyles and outfits, they struck gold. While we basically knew that the concept of customization was in for Sword & Shield, it was just recently confirmed in a roundabout way.
Japan apparently just held a contest that challenged fans to create a unique Pokemon t-shirt, and the winner (a Magikarp/Gyarados mix) is going on to be immortalized in Sword & Shield. This is the first real confirmation that trainer customization is in (besides the outfits we’ve seen in the initial trailer reveal). It’s a small detail, but it’s something all the same.
As for what’s next for Sword & Shield, it seems like we’ll have to wait until E3. CoroCoro magazine (the main source of drip-fed Pokemon news, which slowly reveals new creatures painstakingly over the course of the year) is publishing news on June 21, directly after E3. We can bet on an info dump during Nintendo’s E3 Direct, then a follow-up a week later.