I think they do. I had a discussion with Randy Falcon, who also thinks they do, he said Shine Mouton used to say that the best a reed sounded was right before it broke.
I compare it to a piece of metal that you bend up and down. As you bend it up and down it changes the metal, softens it, up to the point it breaks. The harder you bend it, the quicker it will break.
I've noticed that when I first tune a new accordion, after just a few days playing it, the sound improves. I always play a new one for a week or so, then touch up the tuning before turning it over to the new owner. I think that's why Larry Miller used to offer free tuning after the first year.
I compare it to a piece of metal that you bend up and down. As you bend it up and down it changes the metal, softens it, up to the point it breaks. The harder you bend it, the quicker it will break.
guys who ran PAs back in the 70s and earlier may remember how fragile Aluminum diaphragms can be also -- same sort of principle IMHO...
the pistonic motion over time stresses the metal,
even given the 'super small' movement cycles compression drivers operate with, eventually they will break, given sufficient voltage...
if sufficient voltage is not provided, the older AL diaphragms just start to sound a bit less crisp and dynamic than when they were newer -- with less fatigued metal alloy....
seems like that mellowed response is desirable with the music 'producer' (the reeds of the instrument) and not so desirable with a playback system (a music 're-producer').
remember Gentlemen, that back in the day ca. 1800-early 1900, the quality and quantity of metals the Germans and English (especially steel) used was better than any other in the world. Some of the steel razors and knives I have from that time period from German and English manufacturers are of far superior quality than what you can get today. They just don't have access to the same material. its gone. used up. I have had metal workers confirm this. That the best carbon steel you can get today ain't got **** on the stuff the used back then. I will say that some of the alloys they make for certain purposes today are far superior to anything they used back then, but would that come into play with things like brass and steel reeds?. Just something to consider. Don't know if the older alloys, brass e.g., would follow the same suit as the older steel, but just something to chew on.