During the tournament Sabre made Naito, Tanahashi, Sanada, and Ibushi all submit which is an incredible accomplishment due to the status of the talent he defeated. Now I know that at this point he has come up short against Okada, but is definitely still looked at as a credible challenger. Looking at the booking they made sure that Sabre would be looked at as a credible challenger and gave him the biggest push possible.
For fans that are new to Japan and are use to the WWE style of booking this seems a foreign due to the amount of investment they put in Sabre for such a short gap. But that is likely the reason they gave him such a push at the New Japan Cup. Now with Tanahashi as the next challenger for Okada many would think that Sabre falls back down the card, but I think due to his solid performance in the Main Event he will be sticking around for the time being even if it will be a while before his next shot.