With only mere days left until E3 2019 formally kicks off, more and more publishers continue to tease what they will have to share in Los Angeles. As of this afternoon, Microsoft has now made a rather interesting new tease of its own that could indicate what we should expect this weekend.In a brief new tweet shared from the official Xbox account over on Twitter, it was divulged that "something new" will be shown during Microsoft's E3 briefing this Sunday on June 9. "We invited something new to #XboxE3 this year," the tweet from Xbox simply said.Of course, the easiest estimation of what this could be referring to is that of the reveal of next-gen Xbox hardware. For months now, we have heard rumors that Microsoft will opt to unveil both Lockhart and Anaconda, the codenames of its two new Xbox platforms, this month during E3 2019. While this tweet doesn't definitely confirm that, it adds a fair amount of credence to the rumor.The only other thing that I personally think this could be in reference to is something involving Nintendo. Microsoft and Nintendo have been working with one another quite a bit over the past year and rumors that we've heard in the past point to the collaboration going even further. Maybe the "new" thing in question with this tweet is just meaning that it will be new to the Microsoft conference stage. Up until this point, Nintendo and the Switch hardware hasn't been seen during Microsoft's showing, but maybe 2019 will change that.No matter what this tweet seems to be teasing though, we'll find out for sure four days from now. Xbox's E3 2019 press conference will take place on Sunday, June 9, at 1pm PST/4pm EST.