As an example, the permafrost article you brought up. While there may be portions of the permafrost that have not melted in any interglacial through the past 700,000 years this does not do anything to prove that those areas that DO melt will in fact release a large amount of methane into the atmosphere. Furthermore, it also ignores the fact that CO2 levels are currently far higher than at any point in the last 700,000 years and that temperatures in the next 100 are expected to exceed temps of interglacials in the past 700,000 years.