Yup, it's a bit extreme!

In theorey Austrian landlords have been required to have the wiring tested every time a flat is rented out since 2008 but that law seems to have had very little effect.

There's also a heated debate on whether the law implies that the wiring has to meet current(!) standards or the standards of when it was done.
I decidedly read the latter but every electrician I've talked to so far insists on the former and will actually tell you to the face "Just ignore the law, I haven't seen a potential tenant who asked for the report yet!". Seriously!

My reasoning: the rental property law (short MRG) refers to the electro-technical law (short ETG), which in turn states that any wiring must comply with the regulations that were in force at the time of its installation. Furthermore, the MRG says that regardless of these demands, a 30 mA RCD must be fitted if not already present. Since any new socket wiring needs to be RCD protected anyway why include that paragraph if the wiring has to be brought to current standards anyway? IANAL but the general interpretation stinks I'd say.