The Purim prophecy will still be fulfilled, just on a Purim of a different year.
The apostle Paul believed and taught that Jesus would return in his lifetime. That is absolutely clear in scripture. Yet Jesus didn't return in Paul's lifetime.
The prophets of the Old Testament all believed that the Messiah would come and establish the Kingdom of God in their lifetime. That's also very clear in scripture.
Yet GOD himself did NOT consider Paul or any of the Old Testament prophets to be "false prophets" just because they got the dates wrong. Their prophecies were still fulfilled eventually and will be fulfilled eventually.

If any of you had seen everything that I had seen, you too would had shared what you saw, blown the trumpet and sounded the alarm. Or else, you would had been a coward and not done so.
I would rather share what I see, blow the trumpet, prepare the people, encourage people to repent, encourage people to prepare and be ready, then everything not yet occur until a different year, rather than to be a coward and not blow the trumpet when I see the storm coming.
The storm is still coming. Just slower than expected.
We are now better prepared, and will continue to prepare.
We praise Jesus for at least 1 more year to prepare.
It's now impossible for the Great Tribulation to begin in 2026, until the next Purim 2027 or the Purim of whatever year.
Click here to see undeniable biblical proof that the Great Tribulation can't begin at any other time of year. The Antichrist manifests only on a date of Purim, followed by WW3 invasions and the Great Tribulation 30 days later during the Passover season of whatever year. No other time of year is remotely possible.