> it's hard to believe Germany didn't know about this way in advance

Considering that their spy chief was caught "pants down" in Kyiv when invasion started [0] and had to be evacuated by special forces it is highly likely they had no clue. Unless of course they intentionally orchestrated the whole debacle to look like they didn't know, but that sounds more like a conspiracy theory...

[0]: https://www.reuters.com/world/europe/special-forces-evacuate...