Kharkiv
To me a 3x weekly route from Luton to somewhere like Kharkiv is a bit of a jaw dropper. Eastern Ukraine near the Russian border, not that far from the region with a frozen conflict. Very few Brits will be going there either as tourists, for business or visiting friends / relatives. Ukrainian / Russian citizens generally don't have residency or employment rights in the UK. Furthermore eastern Ukraine tends to be much more pro-Russia compared to the pro-EU west of Ukraine
Yes I know there was a Luton-Donetsk route around 2012 but it didn't last long - the fighting around Donetsk and destruction of Donetsk airport didn't exactly help. Yes I know Wizz already fly from Kharkiv to Dortmund and Katowice. But all the same the announcement of the route still amazes me