The link in your earlier post seems dead, but if we're talking about Nordea specifically (coincidentally, I have worked there many years ago), partial IT outsourcing has always been an option, it has had thousands of external IT consultants, it has used a number of core systems from external vendors in its many banks (in such multinational organizations it's often not that simple to draw boundaries where a department or region or acquisition is often doing things differently with different systems or processes), it had a very large strategic outsourcing deal to IBM in 2017-2019ish, etc.
If you're extremely skeptical that the Swedish government would be OK with handing over the keys to their economic kingdom to cheap digital labor abroad so a company might save some money, then you need to re-evaluate your mental model, because that is definitely happening in reality. They may impose some legal limitations - the exact same limitations as towards any other bank - but they generally act as a normal minority shareholder, demanding the company to be cost-efficient and maximizing profit even if it means outsourcing and offshoring.
If you're extremely skeptical that the Swedish government would be OK with handing over the keys to their economic kingdom to cheap digital labor abroad so a company might save some money, then you need to re-evaluate your mental model, because that is definitely happening in reality. They may impose some legal limitations - the exact same limitations as towards any other bank - but they generally act as a normal minority shareholder, demanding the company to be cost-efficient and maximizing profit even if it means outsourcing and offshoring.