I know people are talking Skype integration here, but... that's the wrong synergy IMO.
If Microsoft had any brains, they'd integrate XBox Live with Discord. All of those XBox chat-rooms, XBox-friend lists, screen-sharing, etc. etc. synergizes with Discord more so than anything else Microsoft owns.
The Discord community does not mesh well with the business (Skype/Teams) community. On the other hand, gamers are the obvious synergy. Stream your Minecraft session over XBox into your Discord server. That sort of thing would benefit both Discord and XBox far more than Microsoft accounts or whatever.