With effect from 24 Jan 2019, Singapore Airlines will be utilising a revised award chart for KrisFlyer redemptions. This move would be the first devaluation since Mar 2017.
Across the board, there will be no changes to Economy Class award redemptions, but increases in Premium Economy, Business, and First/Suites Classes.
You can compare the current award chart here, against the revised one here.
Of special interest are the redemption rates for flights between Australia/New Zealand and Zones 1-4. Currently, passengers on award flights from Australia/New Zealand are able to redeem seats on flights to any destination within Zones 1-4 for the same amount of miles. However with the new award chart in effect, Zone 4 will be segregated from Zones 1-3. This will significantly limit award travel options between Australia/New Zealand and the affected zones in Asia.
Interestingly, there are no changes to the Star Alliance redemption chart. This means that the amount of miles required for redemptions from Singapore to, for example Japan, Korea, Europe or the US East Coast, is actually lower for travel on Star Alliance partners than on Singapore Airlines. Of course, taxes and surcharges may tip the balance in favour either way. It remains to be seen as to whether Singapore Airlines will devalue the Star Alliance redemption chart in due course, since its last devaluation in Dec 2017.