The day that absolutely nobody was waiting for is here: Nikkei brings word (paywall) that Suntory will indeed officially be halting sales of Hakushu 12 and Hibiki 17 this year. Hakushu 12 is expected to be suspended from June, and Hibiki 17 from September. This confirms speculation from earlier this year.
Nikkei notes that this is Suntory's first official sales suspension since Kakubin Black Label in April 2016. The way things are going, I would expect more suspensions to come along soon. Domestic shipments of whisky have doubled in the past 10 years, and Suntory has been unable to keep up with demand.
As for when the suspension will end, a Suntory rep was quoted as saying that "a re-release is still a long way away. Quality remains top priority, and we will continue sales based on quality rather than volume."