I worked in the same IT company for many years now and wile it's true that many people have experienced burnout and had time off. It really depends on the situation if they come back or not. In the Netherlands they have to offer a permanent contract after 2 years in the same company. If you experience burnout before you have a permanent contract then usually the person leaves the company. But if you are there longer, have a permanent contract and play an important role in the company then you usually return step by step, slowly increasing your hours and days back to normal over the period of a couple months. Just taking 6 months off without a return schedule sounds like a scam to be me and for most employers would put you on the track out.