Among Rewrite, Angel Beats, and Harmonia, you don’t really have as much shared staff as you’d think.
Shinji Orito - composer for Rewrite and Harmonia, but Rewrite’s OST is probably done with already.
Itaru Hinoue - artist for Rewrite, Harmonia. Most of the Rewrite art is presumably done with already.
Kai - writing alongside with Jun Maeda and Kashida Leo in Angel Beats, and is writing with a new writer, Nakamura Tsuzuru, in Harmonia.
Rewrite’s writers are mutually exclusive from Harmonia and Angel Beats, and 2/3 of them aren’t even in-house Key writers.
But with all that being said, no info on 2nd Beat after a year since 1st Beat’s release is pretty concerning, given the originally planned release schedule of 6 months in between releases. There are probably shared staff like programmers and whatnot, and who knows what other issues bogging down the development.
I feel like they could spacing out the releases strategically, since I think Baba said that “2nd Beat and 3rd Beat” were being worked on. All in due time, I guess.