It looks like BioWare is going for a less coercive (for lack of a better word) way to get people to try Mass Effect: Andromeda's multiplayer mode than they did with Mass Effect 3. Producer Mike Gamble recently had a conversation with Kotaku in which he revealed some new information about how the multiplayer will tie back into the single-player campaign - though, perhaps predictably, he remained vague about the specifics of the mode.
Maybe you remember ME3's multiplayer and the complaints it aroused. If you don't, here's a quick refresher; the ending of the game was affected by the player's galactic readiness rating, which in turn was affected by both in-game events and the multiplayer. If you were committed to getting the best possible ending (and/or, you know, that less-than-a-minute cutscene with the wreckage and the armor and all), you were pretty much required to devote a lot of your time to multiplayer. This, naturally, didn't work out for players who either couldn't or didn't want to play online, especially since multiplayer had never been an aspect of the series prior to that.
ME:A, according to Gamble, won't have that problem. Apparently they're using something called the Strike Team system, which will allow the player to switch between multiplayer and single player within the game itself. Though it's fairly fundamental, feeding into the meta-story and giving context as to what's going on in and around Andromeda, multiplayer is not necessary for completing the solo campaign.
It also appears that the in-game switching from solo to multiplayer is fairly seamless. Though there is a loading screen involved, it's not like you're going to have to insert another disk or exit to the main menu before you can jump in with your friends. This, too, is a welcome change from ME3, and even though we're still in the dark about the specifics of the Strike Team system this new information is a good sign.