It's "claimed" because the stories of recission are real, and to be expected from an industry that simply makes more profits by cutting costs (due to the inelastic demands of sick people needing health care). This story [1] is from 2009, before passage of ACA/Obamacare.
[1] http://www.dailyfinance.com/2009/09/02/think-youve-got-healt...