Here are the case studies I've found so far:
1. The Phone icon
Hmmm..., when was the last time anyone saw a phone which looked like this? The plastic handle which we used to snuggly rest our face into back in the 1970s and which required a cradle to enable you to hang up was arguably even superseded as early as the '80s and certainly by the '90s with more "contemporary" flat, square designs often with integrated keypads and with no need for a cradle. The icon derives itself from a great big piece of coloured plastic and is nothing like today's phones - as such it's a classic piece of nostalgia celebrating a certain phase of telephone hardware design.
2. The TV icon
Again, typically we see this type of icon which looks like a TV from the past. When was the last time your TV had a visible aerial sitting on top of it? When was the last time the edges of the screen looked curved? ( because the TV's outer casing obscured the actual physical glass of the screen ). When was the last time you could see large visible knobs on the front of it? I'll tell you when, back in the '70s again along with brown & yellow tanned interiors and trouser flares !!! :).
3. The SAVE icon
This one, I would argue might not mean anything to some younger people even now, however it denotes the old floppy disk* which we used to have to save our work onto back in the '70s, '80s and even for much of the '90s. Now of course digital storage has been replaced by:
- Hard-discs in various flavours (internal drives, SD cards, USB sticks, portable hard-drives)
- Writable CD-Roms
- Cloud storage ( remote servers ).
Perhaps, then, there is value in the stability of the icons not having to be reconsidered too much or needing changed. Also, critically, these icons continue to work, nothing is 'broken' and all these icons are instantly recognisable as having meaning against their function.*
Having said this, I would welcome a new, successful icon for "Phone", but think that would be a huge challenge. Perhaps we need to consider not redesigning "Phone" but considering "Call" or "Talk" or "Voice" to replace the usage of this icon - thats probably the best angle into starting to make more contemporary and meaningful icons for today's world.