If they are afraid people will cancel their preorders due to having too much time to play it before launch, I just wanna let them know that’s not gonna happen. I think people who preordered are dead set on sticking to AoE4. If they weren’t they would most probably have tried the game on the XBOX pass for 1 dollar before wasting $60 on it. And the ones that haven’t preordered will most definitely wait for every detail to come out until making the leap, so showing them the game can only help them make up their minds.
They might also be afraid of people getting bored with the game and then cancel their preorders, but that’s definitely not gonna be the case for competitive people, as that’s exactly what makes this type of games interesting to them: the complexity of possible builds and interactions and the shifting meta. The only ones that might consider the game a consumable are people interested in Campaign, but that can easily be solved by limiting the access to just a small selection of missions.
If anything, opening up the game can only get more people interested and wash away all the concerns raised by the poorly implemented showcases. These spoon fed reveals will do little in getting people hyped.