I didn't read the article closely enough, but I'd be interested to see if this methane is released from a stored source or if it is from rotting vegetation.

Much of the permafrost area is a frozen swamp; when it thaws, the swamp plants rot.

In other words, this may be a one-time outgassing of a limited amount of vegetable material, at least in this case. We still have the clathrate gun to worry about.