What is the basis for these statements? He already is disassociated from the Avengers. It was very easy, they just didn't put him in it. All the signs that point to them making an Ant-Man movie also point to it not being in the MCU, or at most, not in the current day MCU. Just because someone's in the solo movie (War Machine) doesn't mean they'll be brought along to Avengers. See how my statements are based on the films and what the filmmakers have said? What are you basing your statements on? You're certain, but no one seems to know why.
How is Ant-Man currently disassociated from The Avengers? Because of a report about the script from a couple of years ago? Marvel is emboldened right now with the success of The Avengers they will be expanding the MCU. I can see them doing one-offs or standalones but Ant-Man probably won't be one of them since he is so closely identified as an Avenger.