Mass Effect 4 is almost certainly going to have multiplayer.
Things are getting real now and I need an excellent Producer to come shape online for the next Mass Effect - http://t.co/L4G3OBAn87
— Chris Wynn (@The1Wynn) February 11, 2015
Although we don't know whether the game will have connected features or a full multiplayer suite, the latter makes a lot of sense. Mass Effect 3's multiplayer did very well for BioWare and was pretty popular. While we haven't heard anything about the financial side of Dragon Age: Inquisition's own multiplayer suite, it's a lot of fun.
The next Mass Effect game will not be called Mass Effect 4 but we're using that as a shorthand until EA and BioWare reveal the real title. We don't know hellishly much about it at this time, but it's said to be quite a different game, and not star Commander Shepard. Recently BioWare said it won't be "Dragon Age in space".