You mean Takashi Mukouda? He's only credited for To The Top.

True, the team is behind Haikyuu is consistent but there were changes in the staff for the new season. It's not the same from the previous 3 seasons.

The ones more noticable that sticked around are the Art Director, the character designer and script writter, Taku Kishimoto. The director, most of the storyboarders and episodes directors change for example. There are also new faces in the animation direction department and quite a lot missing.

it's a pipe dream to believe that they are suddenly being disbanded to prioritize AoT.

I probably should've expanded on this but I don't mean they are disbanding the team to work on AoT. They are leaving Haikyuu for studio 6 but they freeing studios 1, 2 & 3 to help on Attack on Titan. Therefore the delay. When only one of your sub-studios is working on a show that airs soon, they will never be able to finish it in time.

Studios 1, 2 & 3 are the supports of IG. They do key animations and 2nd key animations (plus in-netween). They help the other sub-studios finish their projects. All of them. If you cut the help to studio 6 to help AoT (wherever he is), your project will have to be delayed because your staff got reduced.