Just like that BlackBerry has crushed the rumor that cross-platform BBM will be arriving on June 27th. While BBM is still set to go cross-platform with Android and iOS later this summer, it won't be happening at the end of June.
We had some reservations since it wasn't an official announcement and sure enough the rumors are not true.
We reached out to BlackBerry and this is what they had to say:
On May 14th, BlackBerry announced plans to make its ground-breaking mobile social network, BlackBerry Messenger (BBM), available to iOS and Android users this summer, subject to approval by the Apple App Store and Google Play. While there have been reports that BBM will be available to iOS and Android on June 27th, this is not accurate. We will communicate an update as soon as we have an availability date to share.
So we're not quite sure where @TMobileUK went wrong with their earlier Tweet (which has since been deleted) but unfortunately you have to wait a bit longer to BBM your iOS and Android buddies.