Banks only exist because of profits and control of money, so it sounds a bit suspicious they would allow customers to own bitcoin on their own wallets.
I am thinking how they are planning to make their own centralized wallets, something like it was done in El Salvador with Chivo wallet, but that is just my speculation.
I also doubt bank would allow anyone to hold Bitcoin without revealing kyc customer information, maybe even worse than some centralized exchanges are doing now.

It's possible, but this would be major news in Germany and worldwide, and I didn't hear anything about this.
However, some of their board members and investors probably invested in Bitcoin as part of their portfolio.