I don't understand why this document is seen as some spectacular good news. It's the same policy Germany and most states of the world follow for years.

It's only talking about VAT (not capital gains tax or similar). VAT normally is charged only once in the process from the production of a good or service to the final consumption. An example: If you buy a car, then the manufacturers don't have to pay VAT to their suppliers. The person that must pay VAT is the final consumer.

So if you buy a car with Bitcoin in Germany, you must pay VAT - but only once. According to this guidance you won't get taxed twice because you use Bitcoin, and you won't get taxed when you buy Bitcoin (for fiat) to buy the car.

There were some countries that considered VAT for commercial Bitcoin sellers (some years ago there was also a legal dispute in Germany, but it touched only very big traders that were registered as companies, until the EU court decision ended it) but it's the absolute minority.

Maybe the document is more relevant for miners, because it clarifies that they must never pay VAT.

BTW: the original document is here.