It depends on what you mean by “reunification”. That's a word that carries a lot of different meanings. Models talked about in the past were almost like having a holding company, and then you work out two sort of separate structures from a high degree of autonomy.
I suppose the thing that has changed the dynamics is Hong Kong. Treatment of Hong Kong by Beijing has had a big impact on Taiwan and its view of this.
I agree with Steve. The nationalist mission is all important, and this is part of that, but the nationalist mission is bigger. It's about delivering a vision of a country that is a great power at the centre of the world. That's why this part of that is important, but it's not the whole part of it.