This is true. However, they will make it right for everyone already in the program. I don't think united would damage thier reputation by announcing aviate is closed and give everyone the boot.

If changes are made, it will be like the current one, where they can have people transition under the legacy requirements. They didn't force everyone to go with new changes.

Or, if they drop an airline or close the program, like they did with air Wisconsin, those already in the program are still able to transition. I'd imagine if they suddenly announce aviate is no more, people who were already in the program are still able to transition.