Great news, but I don't find it in the least bit unexpected. I was told sometime ago that England were seriously looking at him for the world t20. Spinning all-rounder, who had a brilliant one-day domestic season with bat and ball, and someone who won't be difficult to deal with if they just find themselves carrying the drinks the whole time.
Basically so long as he didn't badly let himself down with the Lions over the winter, he was on the plane.
That said, realistically his only chance of actually playing is if Moeen continues to underperform with bat and ball. I can't see us picking Rashid, Moeen and Dawson - especially with Stokes already in there as an allrounder too. (Hales, Roy, Buttler, Stokes, Morgan, Moeen, Rashid, Topley, Finn are all nailed on starters in my book if they're fit, plus one of Root and Vince, and one of Willey and Jordan - although the t20s between now and then could yet change that)