The specification bumps in the past were largely due to chip makers able to place more RAM on a single card … when the units were spec’ed out by Apple during the design phase, they went by what was available at the time … later, the chip makers were able to add more capacity to the cards … so it could be possible.
For the new 21.5” iMac, you are locked in to a max of 16GB that is not user upgradeable … the new 27” iMac has four user upgradeable slots … so if the after market RAM providers find a way to offer more RAM per card, it could be possible to go more than 32GB … time will tell …
The specification bumps in the past were largely due to chip makers able to place more RAM on a single card … when the units were spec’ed out by Apple during the design phase, they went by what was available at the time … later, the chip makers were able to add more capacity to the cards … so it could be possible.
For the new 21.5” iMac, you are locked in to a max of 16GB that is not user upgradeable … the new 27” iMac has four user upgradeable slots … so if the after market RAM providers find a way to offer more RAM per card, it could be possible to go more than 32GB … time will tell …