So... about this director and this writer...

404Fox said:
Katou-san (Script, Series Composition) has worked on two items in the broader idol genres, Monster Sonic and Dream Festival (male idols) whereas Aikatsu looks to be in an idols-setting but primarily targeting the Precure audience. I hope he wasn't picked for the purpose of leaning towards a kids audience, since it seems he'd do that well but I doubt Bandai would want that. With Katou-san's record on Series Composition roles, I think we are likely to see an episodic format that would let many different characters get some time in the spotlight.
On the other hand, Watada-san's record as Director is a bit worrying just with regards to the overall quality. As a full-on director of a project, he has been in and out of the Gundam Build Diver series. Nothing else worth noting except a fair number of Episode Director positions. I feel he could go either way just depending on how passionate he is about Million Live.
When it comes to fanservice, I don't think either of these two are shy to the idea of having a bit of light fanservice, but I feel like neither of them would push for it in the first place. I think they would likely stick to the light-hearted tone and energy we've seen from previous idolmaster and other successful idol series.
It also remains to be seen who will be in charge of storyboarding, possibly additional script writers, and the real-life Producer.
Given the studio Shirogumi's record, this show is guaranteed to use 3DCG, if not being 100% 3DCG which would be pretty wild coming from Bandai Namco. That being said, I think what they've shown off lately looks pretty good for CG.

TLDR: I expect episodic format and light-hearted plots, probably won't target kids audience (trusting Bandai), fanservice unlikely, 3DCG in an idolmaster anime, a few important positions are still unannounced.

The worst I expect is that we get some episode ideas that are too dumbed down or plain to be enjoyed by any maturer audience. Katou-san has done hundreds of episodes of kids anime after all.
Thus ends my research report. This is how I avoided doing actual important work for 3 hours lol.

28012001 said:

From what I saw recently in the trailer, it will be based on the manga, or at least mostly, and that manga will be the original manga, just like the original idolmaster in 2011.

28012001 said:

However, Tsumugi and Kaori are there, it means there’s addition into this anime, both didn’t appear in the manga.