That's really an interesting assortment of vintage motorcycles, many of which I've never seen before
But to answer as aspect of the question I think you are asking; I hope manufacturers do not feel the need to create fake engine noises for electric motorcycles of the future.
While the sound of the engines is inspiring, it is enjoyable to me because it is reflecting the genuine nature of the machine, not because I personally love all aspects of a loud internal combustion engine all the time ...as I've gotten older, I'm actually becoming more and more attracted to quiet exhausts
About 20 years ago I did something that is really not recommended for many reasons, where I killed the engine on my FJ1200 and coasted all the way down the mountain from Crater Lake in Oregon. As I recall I had been really enjoying taking-in the quiet of the mountain, which I then obliterated by starting the FJ with its loud aftermarket exhaust, and then wondered what it might sound like to turn off the engine.
It was great. It was much like riding a big bicycle, with just the sound of the wind, tires, and chain... so serene
I thought even then how cool it would be to have a silent motorcycle, to be even MORE a part of the outdoors, as motorcycling is often marketed to be.
So I actually look forward to the unique sounds of electric motorcycles. And they won't be silent anyway. There will still be plenty of mechanical noises, just those that are genuine to that machine!
And just like the amazing performance we are seeing now with the reintroduction of electric automobiles, I think we'll be astonished with the performance that electric motorcycles will eventually bring.
But there will always, or at least for the forseeable future, be a place for the ICE motorcycles and their own unique mechanical symphony