From the BBC website [bbc.com],
Twitter announced on Thursday that it was cutting 9% of its workforce following slow growth of the social network.
"In the coming months we'll be discontinuing the [Vine] mobile app," the company said in a blog.
When he learned of the change, Rus Yusupov (one of Vine's three co-founders) - tweeted: "Don't sell your company!"
A quick search revealed that it's not just a rumor - it appears to be confirmed [medium.com]