JWs have never officially rescinded their view that each creative day was exactly 7000 years long.
That's not unusual for Watchtower. To officially rescind a false teaching would simply draw attention to the fact that they were wrong, not something Watchtower leadership likes to do.
For example they never officially rescinded the teaching that the 144,000 were "sealed" (meaning the number was complete) by 1935 either, even though there are plenty of anointed today, including Governing Body members, who were born after 1935.
Moving away quietly from an embarrassing teaching is the preferred way sometimes.