Here is some interesting news; NetherRealm is looking into Cross-Play for Mortal Kombat 11 and would like to bring it to the game sometime. MK 11 was recently announced and is headed to all systems in April. Here is a list of features that the developers would love to have in the game:
Cross-Platform Login, Friends, Presence, Profile, and Entitlements (coming Q2-Q3 2019 to PC, other platforms throughout 2019): Provides the core functionality for persistently recognizing players across multiple sessions and devices; identifying friends; and managing free and paid item entitlements. This will support all 7 major platforms (PC, Mac, iOS, Android, PlayStation, Xbox, Switch) to the full extent each platform allows per-title.
PC/Mac Overlay API (coming Q3 2019): Provides a user interface for login, friends, and other features in a game-agnostic, engine-agnostic way. Cross-Platform Voice Comms (coming Q3 2019 to all platforms): Epic is building a new in-game voice communications service supporting all platforms, all stores, and all engines, which will be available for free. (For developers needing an immediately-available voice solution, check out Discord, Vivox, TeamSpeak, Ventrilo, and Mumble.)
Cross-Platform Parties and Matchmaking (coming Q3-4 2019 to all platforms)

Cross-Platform Data Storage, Cloud-Saved Games (coming Q2 2019)

Cross-Platform Achievements and Trophies (coming Q3 2019)
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