My assumption is the other way around. The club wanted a big home end...but that takes up more horizontal space than a normal stand and the site is constrained N-S. So the small stand is the compromise for having the big home end.
If you keep the roof more or less the same height all round, you're obviously then left with a load of space at the back of the small stand. So my guess is Meis thought 'why not stick a huge screen there?'
For some reason, in later iterations that was replaced by the (WHL style!) screens at each end instead.
But the point is, I'm pretty sure the "biggest screen in Europe" was something that emerged from the necessary compromise in the layout. It was not the cause of it - that was the big home end combined with the site constraints