I don't think that's a given, or even necessarily a strong likelihood. A majority of Scotland's trade is with the rest of the UK, unlike the Brexit situation where a shrinking minority of the UK's trade was with the rest of the EU, the only EU member for which this was the case. Scotland is accustomed to deficit spending and to large subsidies from the rUK, neither of which would be epecially palatable to EU finances.
And while I certainly think it's fair to describe the UK economy as a sinking ship, I also think that blaming that on Brexit is, to put it politely, "starting with your conclusion". UK growth has been higher than France, Germany or Italy since 2016. Brexit has obviously had impacts, but they haven't all been negative (the City in particular has zero enthusiasm to fall back into any EU alignment) and I think the COVID lockdown shambles and the Homerically inept current government have been bigger factors.
And while I certainly think it's fair to describe the UK economy as a sinking ship, I also think that blaming that on Brexit is, to put it politely, "starting with your conclusion". UK growth has been higher than France, Germany or Italy since 2016. Brexit has obviously had impacts, but they haven't all been negative (the City in particular has zero enthusiasm to fall back into any EU alignment) and I think the COVID lockdown shambles and the Homerically inept current government have been bigger factors.
I found this a decent recent overview on the common analytical takes, if you're interested: https://julianhjessop.substack.com/p/what-the-nber-gets-wron...