To be fair, about ONLY event event Aigis - and so DMM devs in control - skipped forever is Liana. Because lolshrineblack. Elisa was looking to be next event after Anna. Everything else was released already.
EXP Fairy is a recent'ish addition to DMM, around third anniversary, while we were around second anniversary event-wise. So really, not applicable.
There's also Osawari Island that Nutaku (well, some English mobage devs affiliated with them) is running even past closure of DMM side from what I heard.