I don't think "coming down from the rafters" means "in a state of great excitement". It's not an expression that normally has that metaphorical meaning and it's not logical that it should; "coming down" expresses the opposite of excitement in metaphorical terms.

I don't think it's a metaphor at all; I think it's literal. The idea is that this match lasted an extremely long time and continued late into the night. The first speaker says he went to bed before it had finished. The shot we see of the stadium show many empty seats and people moving around. Many people had left before the end, because it went on so long.

The seats lower down near the court tend to be very expensive and are often occupied by people who not there primarily because of their love of tennis, but rich people attending the match as a social occasion. The real sports fans are seen as the ones in the cheapest seats, high up "in the rafters", furthest from the court. These are the spectators who really want to see how it finishes and will stay all night if necessary. Since better seats have become vacant lower down, these real sports fans come down from their own seats "in the rafters" and sit in vacant seats near the court.

Just after this a speaker says there were 4000 people there. This is very few for such a large stadium. What he is saying is that the stadium has largely emptied. Those left are the real sports fans.

The same thing happens in the theatre and the opera (I speak from experience). Many real fans sit right at the top because they can't afford the expensive seats below, but if there are free seats in the stalls they come down and occupy them.