Hingis teamed up with Vandeweghe afer splitting with Mirza mid-season last year. The duo reached the finals of their first tournament togeether in Cincinnati and then made the semi-finals of the US Open. But since then, their partnership did not yield many successes - going 5-5 in their next five events. Hingis played the St. Petersburg Open last week with countrywoman Belinda Bencic.
Chan is ranked 12th in the world and has won 18 WTA doubles titles, half of them coming with sister Hao- Ching Chan, including the Taiwan Open earlier this month. The Chan sisters have said they will be taking a break from their partnership, which has opened the way for Yung-Jan to partner Hingis. The two are expected to start their partnership in Doha.
I think this is a good move by Hingis, she wasn't getting any decent results with Coco, who in my opinion is a better singles player (and it seems to be her main focus anyway).
Chan is an accomplished doubles player only so, this could work. Fingers crossed.