From what they have said in the past, some of them probably are. It isn't like Paradox (or most other Swedish companies) completely shut down for the 'Holiday'. It is just that A) the (full time) employees are entitled to a paid vacation during the summer, B) the employers are prevented from saying no (during the summer, except in certain exceptional situations), C) it just makes sense for the majority of the employees (and for the employers to encourage them) to take their breaks at the same time, and D) it makes sense for the company to go into 'low activity mode' while the majority of their employees are away.
It could be that some of the employees left 1-2 weeks earlier, which means they might be back by now. And some of them could have started their breaks 1-2 weeks later, so they might not be back when the company starts to get back into the cycle.