That edition of Samira Ahmed's Newswatch included an interview with James Stephenson, News Editor for BBC News and Current Affairs (the man who has just made anti-UKIP Jasmine Lawrence his deputy). During the interview he said that the BBC will be broadcasting more EU referendum-related programmes like Europe: Them or Us over the coming weeks, and that "Mishal Husain will be looking into migration".
Wonder if that's anything to do with the BBC's World on the Move Day - an all-day, multi-platform 'event' focusing on migration that will fill the BBC's airwaves on 16 May? The BBC's press release says that Mishal Husain will have an important role in that too - though it doesn't connect the event to the EU referendum.