Good news! The devs behind Warframe are interested in cross-platform play. Bad news! It sounds like achieving that would be monumental task. Here's what Warframe creative director Steve Sinclair had to say on the matter.
"As a player I would love it. As a developer, it's one of the highest-risk things we can do. Because a lot of the games that are doing it—it's still very early days for this—A lot of those games came late to the platforms and had different negotiating environments to establish their contracts. On top of that, we are a game that is constantly changing. We change the game modes, we change the gameplay. We do huge, huge swings constantly, so, it is something that we're all interested in and we do discuss it."
Something that is more feasible is sharing progress between platforms. According to Mr. Sinclair, it seems the team might focus on that path moving forward.
"Those things are a lot more doable than getting everything in sync and doing complete cross-play. Maybe it's more of a gradual step for us than an overnight switch."