Bitcoin and other cryptocurrencies are treated equally to legal tender in Germany.
I’m sceptical that you spent 20 years in fintech without learning the definition of legal tender.
If you go to a restaurant, eat your meal (thereby accumulating a debt) and slap legal tender on the table, the restaurant must accept it. They may also accept other things, like Visa credit cards or Ethereum. But they aren’t obligated to. The former is legal tender. The latter is a way to pay. Obligations around settling debt are the sole defining characteristic of legal tender, so it doesn’t make any sense to say one thing is “treated equally” to legal tender if it lacks this core characteristic.
If you travel abroad you may have to exchange your currency to pay for a meal, because your coin is not treated equality to legal tender locally, and the defining characteristic is that it settles the debt at the time of exchange. I believe that's a function that cryptocurrencies fulfil by design and if the court states they are to be treated equally to legal tender that seems to prove my point.
The German source says that for some purposes it is "treated equally to legal tender" and that "exchanging virtual currencies to legal tender and back is tax free". Neither statement makes sense if it were legal tender.
Its status for some purposes is similar to that of other non-Euro currencies (e.g. contracts between private parties agreeing on it etc), none of which are legal tender in Germany.