That's a lot of added seats from SAS, I'm sure it will come with smaller aircraft on many rotations (we often get a 321 from CPH for example) but still, I hope they can fill them all.
With regards to a taxiway bottleneck these things can be modelled in the planning stage and I'm sure MAG will be given estimated delay times and capacity figures for various options. I would hope that they are clever enough to spend the money properly now when they're already investing a large sum. No use doing something like this halfheartedly (IMO).