Update 9/24/19: Reposting this since tons of people are starting to notice they got their IT card changed to Miles. Some got emails and some did not. You can call in to get it changed back. (They might tell you to wait a bit before being able to change back.)
Update: Looks like Discover often does this when they card hasn’t been active. You can call in and request a change back to the Discover it card.
Original post: @milesperday & @unknowntree have received an e-mail from Discover saying that their Discover it card will become a Discover it Miles, this is despite not asking for this product change to occur. I suspect this was sent out in error, but it’s possible that Discover is no longer allow people to have multiple Discover it cards. Having multiples is useful due to the rotating 5% categories, whereas the Discover it Miles is not useful as it only earns 1.5% cash back.