With this digitally connected world, when a friend leaves the city that doesn't have to be the end of the friendship. One of my best friends moved to another city 3 hours away. We still talk or text a few times every month. We meet in person a few times a year when they're in my city or I'm in theirs. Sometimes we drive to meet at a third city between our two cities. We've met up and gone on multiple vacations with each other with our spouses. He moved away over 25 years ago to be closer to family when he was raising his first child. We certainly had busy lives of our own in adulthood, but that doesn't mean we lost that friendship. We are still close today.
Is it possible some of your friends feel the same about you where they believe the distance won't diminish your friendship? As in, they do have lives and commitments they have to do so they don't have the opportunity to meet you before you finally move, but that they fully expect to be in your life even after you leave your city so they don't see missing a final dinner in your city as final?