Autonomy is not the same as statehood. Autonomous regions within states are absolutely fine with the EU, so I fail to see your point. If Catalonia becomes a state it will no longer be in the EU. It will have to reapply, and, for several reasons, will find it next to impossible to join. First, a unanimous vote by all the member countries is needed for a new member to join. I can't see Spain voting yes somehow. Second, there are other countries with unsettled regions such as France with the Basques. Neither the EU nor Spain would not want an eased path for Catalonia to give others ideas. Third, the whole concept of the EU is predicated on closer harmonisation, countries splitting apart being completely at odds with that. The odds are that an independent Catalonia would be out in the cold for a very long time. That prospect alone would be sufficient, I reckon, to lose an independence referendum. Spain should cool it and allow Catalonia a legal referendum. I don't believe in 'em, as I've often said, but the two sides are locked into an impossible, conflicted situation for the foreseeable future without one and there's no other way. I don't think Catalonia is going anywhere, whatever happens.