I believe only cards from 2014 or earlier have been required to be replaced so far.

People who had an octopus from the initial batch of 1997 could have used it for over 20 years and the deposit is still refundable, albeit with the aforementioned fee since 1.5 years ago. Meanwhile, many transport smartcards around the world have to be re-purchased every 5-10 years with plenty requiring a local bank account to get any refund of the cash balance