Just curious.

Is there a time one could expect Gate shown on the departure board? I assume a plane dropping down will not come as a surprise to anyone, gate should be allocated quite in advance, no?

Following on that, could one expect a delay at some point, if no departure gate is shown? I might be biased and misinterpreting, but I quite often see very late gates on the ARN flights I take, between 10-14. Seems to always have late gate no. on the board?

As an example. I am on BA 778 today. Flight are supposed to leave in 45 minutes, still no gate.