From Friday, May 27th, until Friday, June 10th, there’s a new seasonal questline in place to attract player attention. There are also three event-exclusive rewards available: a new housing trophy, a new emote, and a firecracker that rains money from the sky. (Not quite “making it rain” in the traditional sense, but still.) Last but not least, all MGP gains will be increased by 50%, making it that much easier to farm up the currency and get the items you really want within the prize selections.
Source: Event page, event overview