During our trip earlier this month they were actually advertising that you can add days to your ticket up to they expire or 14 days from first use. The ad played on the monorail over and over.
I am not a bit surprised at this.
That was the way it was for years and years.
Then, about three years ago, they started to disallow guests to upgrade stand-alone tickets
any day after the day that the last asset had been used.
That idea was to attempt to stop the unlawful re-sale (transfer) of used tickets.
Even during those times, guests staying at a WDW resort whose tickets had their
name printed on them (by Disney) were allowed to upgrade a fully-used-up ticket
as Disney could keep track of if that ticket was being used by the original owner.
But, NOW with nearly everyone linking their tickets to an
MDE account,
an account that connects to a specific individual, it makes sense that they
can allow upgrading fully-used-up tickets under most any circumstance as Disney can keep
track of if that ticket is being used by the original owner.