I was saying the exact same thing to a travel agent yesterday. I think they will get really busy. Also because they got all the C-stuff one needs to know. As a vaxx-free person, I need to check with each and every airline now which is difficult if you use more than one. See, I got a different problem now. While I can still leave NZ, I won't be able to come back without the pass. Means Bryan as a kiwi can go to Tonga and come home, but I can't because I am not kiwi though I live here. Traveling made difficult.
Online booking? I usually get really frustrated. So, a 3-day vacation would be a nightmare for me to book. Good luck with that and please stay sane :-).