Wasn’t there a Sony Channel before?
Yes, it closed last year.
It had some good first-run comedies like Community and Younger.
It also had repeats of classic British TV shows like Spooks, Hustle, Life on Mars, Ashes to Ashes and Hotel Babylon.
Mars and Ashes have both shown up on Drama. Maybe the BBC yanked the content to give to UKTV, and that left Sony Channel short of programming?
Those shows are all Indie productions and are outside the standard BBC licensing period - so the indie can sell them to whichever channel they like.
If a show is commissioned by the BBC from an indie (*), under the standard BBC/PACT contracts, the BBC only have rights to show that show for a limited, licensed, period - and don't have rights to sell it on to other broadcasters, or to show it on non-PSB outlets. The indie can decide to market the show via BBC Studios (formerly BBC Worldwide) - but the BBC doesn't 'own' the show.
Rights to programmes made by BBC Productions, or produced more recently by BBC Studios (which is the commercial, programme-making subsidiary of the BBC - making non-News, non-Sport, non-Kids shows) remain with the BBC and the BBC then sells them on.
(*) There are some former BBC-produced shows (Songs of Praise, The Proms. soon Mastermind) where the BBC has tendered the production of the shows BUT not the long term rights. The rights to these shows remain with the BBC (the Proms is a more complex rights case of course).