This is normally the timeline I've seen on this board:
12:00 PM--Country X announces the need for a green passport/vaccine passport/QR code
12:05 PM--The posts here begin--"What about us who are traveling there?"
Please remember, when a country decides to put restrictions on movement due to Covid, they are first thinking about their own people. They are not worrying right away about American tourists.Or Canadian tourists. Or Chinese tourists. They will get to it one way or the other. You need to be patient.
I guessed that the opening would not be without issues and decided to wait to travel until the fall. I hoped, and still hope, that everything will be worked out by then. But what I don't do is assume that what country X is insisting on today will be the same in October or later. I have a feeling rules will change many times before then.
I am just as eager as anyone to get back to international travel but I also didn't want to have to go through all the canceling hassles I had last year.
YMMV
By the way, when I read that some countries were opening up to tourists without asking for proof of vaccination nor a covid test, I got the feeling this was a recipe for disaster. While they might say those vaccinated don't have to wear masks, many unvaccinated will go without masks as well. And with this Delta variant, the spreading is widespread. We only have to look at our own country (USA).