Yes, it's oddly specific but apparently intended to allow countries to classify energy from such plants as "green" and treat it as such when buying/selling or taxing it. That is important because a lot of companies that are interested in buying green energy in order to reduce their carbon emissions would care about their energy being labeled as green. There is a lot of book keeping that is happening related to this and some big financial interests across the EU. Demand for non green energy is going to be dropping as companies shoot for being carbon neutral and are incentivized to switch to green energy.

The Germans are going to have to build a lot of new capacity until 2030 because their new government just committed to closing all their coal plants by then. Inevitably, that's going to involve building some new gas plants. And those won't be green unless they meet those criteria. So, that construction permit end date is interesting here. This clearly is a stop gap solution so Germany can get rid of coal and build some "greener" replacement plants without creating a demand problem for energy produced by those new plants. If they weren't green, lots of companies would end up buying their energy from other suppliers.

After 2030, the attention will shift to getting rid of natural gas completely; hence the further restriction of having a plan for switching to something else. Natural gas is already a bit on the expensive side and lowering the carbon output won't help with that. But it's going to take a bit longer.

Nuclear is in there because lots of countries in the EU are still building new nuclear plants and they don't actually emit carbon. So, calling that green is a lot less controversial.

So, odd but I can see the logic. I don't necessarily agree with it though. If it emits carbon, it's a problem and as a consumer I would not want to be tricked into buying "green" energy like that. People are going to notice this and call bullshit on that.