I don't think this would have a huge impact though, to be honest. The banks will still not want to work with crypto-currency and definelty not bitcoin, when it is literally the opposite of the values that they support.
It's going to make the small amount of banks that wanted to work with bitcoin easier to do so, but no one is going to start jumping to offer crypto services.
What's the exact date for this issuance BTW? So, I'm assuming banks can't work with BTC and other cryptos rn?
Banks can work with bitcoin, but there is a risk they will be tempted to do fractional reserve. If they don't, then naturally custody fees would need to exist. Its probably not going to have much demand, but it might entice some people in Europe that were more skeptical before.
As i have said before, banks have the opportunity to be exchanges, they could even get into lending, but it would be highly unethical if they did following fractional reserve thinking, and it will surely lead to drama later (bubbles and crashes, bankruns, etc).
Since all bitcoins always have to be accounted for, they can't really pull this off as easily as they can with fiat. The blockchain can always tell you in what wallet a coin is, and unlike fiat they just can't make bitcoin out of thin air. With fiat they can work with a fraction, because you don't care what serial your banknotes have, and you don't follow the serials of the banknotes that you deposited.
It would be better if the law somehow blocked the banks from fractional reserve practices, which might be the reason some countries treat bitcoin as asset rather than "money". You are not supposed to have fractional reserve of your gold ingots, for example...
In the end the whole world needs to adopt Austrian school economics, there is simply no other way.