The phrase "recent livestream" refers to a recent live video broadcast that happened online. It involves someone sharing or streaming live content, which can be watched in real-time by others. Full definition
Ubisoft showed off the new map, Beachhead, during recent livestream, which you can watch below (jump to the 1:36:30 mark for footage of the map). (wccftech.com)
This most recent livestream showed off Mercury and what players can expect out of end game content. (xboxoneuk.com)
Recent Livestream also reveals some few features that the fans should expect. (gamenguide.com)