It wouldn't be surprising at all. Authoritarians, whether fascist, socialist, communist etc, want power over people. What better way to get it than to remove the ability to use money that has objective value? With fiat they can inflate the value away so that you lose half your purchasing power in 30-35 years (or less). With fiat they can control and censor people they disagree with. Look at Germany shutting down a political party. Look at France using the legal system to attack an opponent. Look at the US using the legal system to attack Trump. All pretty fascist techniques but certainly the rest of the authoritarians love using them too. Look at Cyprus in March 2013 with the capital controls.
Smart people in Europe should be putting some of their wealth in bitcoin so that they have a way to escape the carnage if worse comes to worst. And not in some centralized ETF or similar vehicle. Ditto the US so that if the far left extremists ever regain power and start attacking political opponents (e.g. using the IRS to do so as under Obama, using the legal system to do so under Biden etc) people in the US have a means to protect themselves.
Will they ban it? Yes, if they can't control it to their satisfaction. Will that happen? Who knows.
IMO the EU is, like you said, an authoritarian leftist regime. After all it was established by Spinelli, who was a communist, focused on redistribution of wealth and open borders.
Whet the EU wants is to completely remove local governments and make countries obey the central government. The deal is, like in Orwell's vision, the pigs will always find a way to put themselves above the rest. Nowadays you can observe a division into founders and the rest of the EU. Germany and France want to lead the sheep and we'll see whether they can succeed or not. I hope that people will eventually wake up and see through their plan.
If bitcoin threatens their precious CBDC plan, it will have to be banned. The important part is member countries can still veto this, but the EU wants to remove the right to veto. You have to be dumb not to see where it's all going.
The EU has some good parts like regulations against corporations that abuse their terms of service, the US is lacking on this regard. However, too much regulation can stagnate growth, so you should a balance. It's one of those things. Now when it comes to the BTC problem, no government wants to lose power of their printing press, and their ability to keep their debt yields in control, and if they think that people may buy BTC instead of their bonds, then any government, including the US, will ban, or otherwise tamper with BTC usage to the point of making it nonviable. Trump is supporting BTC because he found a big voter base, but the moment another guy goes in office, they may revert it back to where it was, so it could be the same in the US with Warren, AOC and so on, if they gain power again in the future. The reasonable way would be to find a common ground with enough regulation but also not making it useless by taxing all transations, putting people that use mixers in jail and other nonsense.