Matthew Vaughn had indicated that the film will see the return of not just Eggsy or Colin Firth’s Harry, but also the teams of Statesman character that were introduced in Kingsman: The Golden Circle.
As Taron Egerton states that he’s not allowed to talk about it, we certainly don’t get much detail about what the next proper Kingsman movie could possibly be.
It seems that, since the last movie left all of these characters in new places, the next film will follow them as they navigate their new situations.