Maybe just other usages of "im Urlaub" greater, like "im Urlaub erlebten wir das und das", "im Urlaub hatten wir schönes Wetter" and so on. "In Urlaub" as in presently remaining there, appears fully wrong in Upper-Austrian, but I don't find out about the Germans. I have also heard about https://bihlmayermedia-bilder.com/urlaub/wir-sind-im-urlaub/