It really sounded like a splash and I fliped out.
My GF and I were watching the cutscene and we both just looked at each other.
Yeah, I kind of flipped when I watched it too.
SO ANYWAY! I've finally come to the conclusion, that should DIMINISH your thoughts of it being static. I've done my research. And I've come prepared.
So, I believe that Giovanni jumped off the falls. First of all, the sound. Yes, debating on static and splash... which one is it? If you've played it, or watched the video, at least... you would've known by now that the sound PLAYED at the EXACT time the radio started speaking. So, how do you think the radio would be able to "talk" when static's going about? Second... do you know what would happen if you lose to Giovanni?
"Giovanni: Not being able to measure your own strengths shows that you are still but a child." -Leaves room-
Now, let's go back to how the story should go. When he leaves the room, there's a splash, right? But when you lose to him purposely, he exits the room WITHOUT a splashing sound. Then Celebi just teleports you back to Ilex Forest, and you'll be able to do the event again... and, there's no splashing/static sound. NOW YOU SEE, if that WAS a static sound, why didn't it SOUND when Giovanni LOST? I mean, it technically happened in the same time, just with different events! The fact that there was NO sound when he exited when you lost, makes it clear that it was INDEED A SPLASH. Now, I can't say for sure that he did suicide. But I'm sure, something fell on the water. Whether it be Giovanni, or just an item. I'm sure; it's supposed to be important. Why'd gamefreak do that?
For those to disprove me (Pokemon is a child's game blah!):
Remember when you got the GB sounds from the guy in Celadon? He says something about nostalgic feelings... obviously, if it was just kids playing HG/SS, they wouldn't have the nostalgic feeling cause they didn't grow up with GSC. Now, the fact that he mentions nostalgia means that it is also aimed for the veteran Poke-players. Yes; while it is not entirely for the veterans, it's still a heads up. Now. E rating... why is it "Everyone" "ESRB Ratings not rated for online interactions," it says. Technically, Celebi/Giovanni event is in-game. But. You need Wi-Fi to get Celebi, which, technically as well, makes it an online interaction. Now. Why Ethan/Lyra's reaction was bland... well like I said earlier. Although it is a heads up for veteran Poke-players, it's still a child's game. Children can play that part, too. So if you were a child, you wouldn't dawdle much about that fact. But if you were the veteran, having experience and stuff... you would have to speculate about that sound.
There goes my debate. Disprove me; I'm open. But I'll come back armed... well, unless you hit me on a spot. And I crumble to pieces... but I'll stick to my belief, unless you can counter mine.