Just for kicks I went and checked this all out:
Feb 3, 2013 Juice=Juice formed -> Sep 11, 2013 major debut
Nov 5, 2014 Country Girls formed -> March 25, 2015 major debut
Jan 2, 2015 Kobushi Factory formed -> Sep 2, 2015 KF major debut
April 29, 2015 Tsubaki Factory formed -> Feb 22, 2017 TF major debut
May 5, 2017 KSS debut announcement -> August 7, 2019 BEYOOOOONDS debut
July 11, 2019 1st KSS Unit -> July 13, 2022 OCHA NORMA debut
June 29, 2022 2nd KSS Unit -> March 29, 2025 Rosy Chronicle debut
So approximately:
JJ: 7 months
CG: 5 months
KF: 9 months
TF: 22 months
BY: 28 months
ON: 36 months
RC: 33 months
So something seems to happen in between Kobushi's and Tsubaki's debuts. Of course, TF was getting their crappy indies releases so it was only with Biyo that we spent a year or more getting nothing (although in their case that continues after their debut). I suppose if you account for OCHA possibly being extended due to covid happening in the middle, you could still make the argument that they have been steadily getting longer.
Anyway while I am excited for this (and especially for baby Yulia finally getting out of KSS), I hope we're done with the new groups for a while. There'll be seven now, five of them are now immortal generational groups, Juice and Biyo barely release anything, and looking at the dates above, there's been a new group in some stage of development nearly continuously for the last decade. I think it's time to take a breath
(But also, to give Mifuru a single dammit.)