I think something akin to this, maybe even this itself may become permanent. Why ?

If you take a look in the medals shop you can see they added the AA (Amplyfied Ampys ) there.
If those AAs were available only for this event they would make a separate tab just like we usually have for the event girls.
Them being part of another tab, means they will stay. And since they stay - some way to farm the currency for those must happen as well.
It can either be the Nidhorog (or wtf is the name of that thing) or maybe some new permanent map will be added so we can farm those Super medals.
Maybe they might even combine it with the regular Sun medals, thus you can use those later on for both. We ´ll see.
What I want to say is that I am sure we get some sort of permanent thing going on for these. Unless they wanna make this literally a "MMO Event"
just like with the Whaleship - Where the mega boss maps open once every few weeks, like a Raid in MMO where you need to run it during limited time period to get as much as possible. and then wait for the next reset.