I had this issue too and contacted Sky by email but I'm not sure that they really understood the issue given their (admittedly quick) response.
I eliminated the Sky app from my Apple TV and factory reset it, then it asked for my password to re-enter but didn't recognize my password. Hmmm.
Then I discovered that my Iphone and computer were out of sync.
I realized that something was up when I couldn't send text messages from my laptop and asked me to sign in. I changed my Apple ID password, rebooted my phone and computer and they started to speak to each other again. I just turned on Apple TV and Sky News started up without those commercials overriding the program.
Might be a coincidence or Sky realized that there was a problem. Whatever, things are back to where they were even if it took me a couple of hours to get things sorted out.
Maybe worth a try?