Doesn't look good. Any art's biggest strength comes from the understanding of color. Which color to use where. For example, Stain's speech. Even in real life directors go out of their way to shoot scenes at specific times if they are using natural lighting to make it look as good as possible. The Revenant for example. Sky is a very important part of cinematography for outdoor scenes. For MHA, we are watching a war, not a adventure (even though that is the genre where you have to make the background look the best)
And it's not like MHA has never done it. The speech annoyed so many people because it didn't look in place. We see then pull this off great with Muscular in the same season.
Also it's not because it's a blue sky, but because it's the same blue sky. Sky doesn't stay the same shade throughout the day, it changes, the sun's position, clouds, wind and even the ground affects it.
Take this shot for example
looks great, because the clouds have shading and the brightness makes sense at this altitude. You can see the wind currents affecting the clouds.
But then you have Deku vs Shigaraki with a flat two note gradient and clouds with no shading.