Watch this video from 4.00 on and then see when it was posted.

And here's the EBU's response:

Statement on performance of Ukraine's winning Eurovision Song Contest song before September 1 deadline:
"The Eurovision Song Contest rule (1.2.1a) which states that entries must not have been commercially released before September 1 exists to make sure that the Contest can welcome new compositions each year, and that every song can compete on a level playing field.
The purpose of the rule is to prevent wide distribution of any song that might give it an unfair advantage in t...he competition the following May.
In the past, songs that had been publicly available before the deadline, but had not been accessible by a wide audience, had been granted permission to compete in the Eurovision Song Contest by the Reference Group.
In the case of Jamala’s “1944” the EBU’s attention has been drawn, after the 2016 Eurovision Song Contest, to a public performance of an earlier version of the song in May 2015.
The video of a small concert had only been viewed by a few hundred people before it was discovered in the past few days.
The EBU, based on previous decisions in the Reference Group, therefore has concluded that the published video did not give Jamala’s song any unfair advantage in the 2016 Eurovision Song Contest and the song was eligible to compete.”

PS The video has now been made private

Yes, as expected, and consistent with what they did in other similar cases - ie, SunSay's Love Manifest. The video can be viewed here:

Usual rubbish from the ebu first they let her take part with a song which shouldnt have been allowed now this crops up and again they do nothing. They need to burn their rules book as they never take any notice of any of it the whole thing stinks