But I don't believe that's quite accurate. Some were forced to switch doctors because the doctors moved to other networks, and some were forced to switch plans because their cheap but nearly worthless plan was canceled by the provider. The ACA allowed them with a grandfather clause, but what Obama didn't talk about was that providers weren't compelled to keep providing those plans. That was Obama's "lie by omission."
The fun part is that it was common for insurance companies to drop plans and doctors long before the ACA went into effect. During one year I had to choose a new primary care physician three separate times because the old doctor had been dropped from the insurance company list.
But apparently Obama not spelling out every detail of a complicated plan made him just as bad as Trump who tells easily debunked whoppers several times a week.