Connection to XXX and XXX2

It references the first 2 films at times, in ways that definitely improve the viewing experience. But as long as you have a basic understanding of the xXx premise, it's also good as a stand alone action flick

Basically, with xXx 2, we come to find that Xander Cage has been killed (false actually) & subsequently replaced with Darius Stone (Ice Cube) who becomes the new xXx. And, at the end of that film, it ends on a cliffhanger discussion between Gibbons (Samuel L Jackson) & a separate character from that movie played by Scott Speedman, where they ask "Who should the next xXx be??"

So its basically a B-rate James Bond type of role. And so Return of Xander Cage definitely works off of that premise, yes. But no, the first two are not mandatory, but its cooler if you saw Ice Cubes xXx beforehand

Well if name and some cast is relevant then watch the first movie. Not a spoiler because of it was in the trailer but this time it was the military guys going out the back of the plane.