Yes, pretty much.
Speaking of, I'm still missing some of the earliest ones like Southern Cross (the latest permanent event when I started playing in Christmas 2016) and those starting from Lunaria to Fuchsia. I have everyone from Gazania onwards.
No upgrades.
Congrats on the triple Oni, my dude!
For the length of time I've been on DMM and with the roster I have (>20 rainbows), it's only as valuable as a truckful of bond crystals (which I still have more than enough of) to me. Plus, Kugaisou [link] is 900 FS cheaper and brings a lot more to the table for almost the same cost, being a rainbow with solid abilities.On the side note of this, I definitely don't see much of a point in this for me. They've already come full circle to the events when I first started several months ago. I have gradually worked on picking up the other event girls ever since I started DMM. So with having these event girls with their levels/equip slots already unlocked, it's kinda pointless to pick up more copies of them. Now for a newbie to the game, this is a pretty sweet deal. I'd also say a great time for any Nutaku player to come over to the DMM side and quickly get them all as they start again.
I wouldn't mind going the long cut to get the rest I don't have. That said, I actually have an excuse to revisit permanent events I haven't played thanks to post-Nidhogg stamina cuts. It's been like ages since they had 30% off, and I didn't really want to farm them outside of said campaigns.