I think they'll take longer for this comeback like they did with More & More
Their Korean comebacks usually have a 4-5 month difference between the previous comeback
Since Scientist came out in November that means the comeback would have been in March-April(More likely April since they have had lots of comebacks in that Month)
But I think it may take longer this time (I'm guessing August)
I do think there will be a Japanese comeback before a Korean one