As we had no new contents in April, except for the SDX Delivery, my guesses are that the kits might be released one close to the other.
If they are not going to release them together as they did for the 3 first kits and the Fashion Streetwear and Incheon kits (that came out in the same day), then they might be released just 7 to 10 days apart.
But if they are going to release an EP (as speculated both here and on twitter) in July, I doubt they will wait June to release the GP, so they might release it before the end of May.
I also expect a refresh somewhere between May and June, because there are too much hints for it and I'd be disappointed to only have a kit about "camping in the backyard"
