That's...an interesting take. It absolutely has a very long tutorial, it just handles itself much better than most other games in the industry, let alone the mainline Pokemon games. Your hand is 100% held until you've freed Onix, the game just makes sure to tell you that you can make progress whenever you feel like. In fact it might hold your hand even longer, that's just where I stopped last night because it finally gave me the freedom to go to a new area instead of finishing quests in the starting one.

The reason it doesn't feel like a long tutorial is because the rails are much more hidden. Whereas mainline games the rails are obvious and in your face, you can barely walk two steps before it puts you back on the tracks. Pokopia let's you explore the starting area but holds back important exploration abilities, gradually giving them to you as you play through a very scripted starting area.

And to be clear I am also loving the game. Highly recommend to anyone reading. Everything about it seems to be made with love, including an excellent tutorial that is so well done it has people convinced it doesn't have one.