Update: Additional info has come to light that suggests this T-Mobile tweet may have been issued prematurely. See below for details.

BlackBerry Messenger is reportedly coming to iOS and Android on June 27, according toa tweet from T-Mobile UK’s official account today. The tweet was accompanied by a picture of BBM in action on a Samsung Galaxy smartphone. We knew it was coming, since BlackBerry announced it would be arriving “this summer” back in May, and that it would be free on both platforms and require either iOS 6 or higher, or Android Ice Cream Sandwich or greater.

Great news – BlackBerry Messenger will be available to download on iOS and Android from June 27th!  #BBMhttp://t.co/PbG1uknM3h—
T-MOBILE UK (@TMobileUK) June 06, 2013

BBM on other platforms will initially offer just messaging, but BlackBerry CEO Thorsten Heins said in the service’s announcement that they’ll be adding more features over time, including screen sharing, BBM voice and the new BBM Channels. Making BBM an independent product is a dramatic, bold step for the company, given that it is often cited as a key competitive advantage that BlackBerry still maintains over its rivals, but the company is clearly keen to look at survival strategies that go beyond making a comeback as a smartphone maker.

BBM isn’t the only fish in the sea anymore, however, as there is now an amazing bounty of mobile messaging platforms to choose from on iOS, Android and even BlackBerry that offer similar functionality. In fact, in a worst case scenario, it’s easy to see BBM launching on iOS and Android as giving license to disaffected users to leave for what they perceive as greener pastures, while taking their network and social contacts with them.

Still, this is a calculated risk, and BlackBerry must see a very clear and present upside to opening up its platform beyond BB OS. It definitely has the network volume, which is generally the goal of pre-monetization startups launching similar products, so we’ll see where it takes things from here. We’ve reached out to BlackBerry for direct confirmation, and will update this story if we hear back with more information.

Update: Business Insider says this date is “incorrect” according to its own sources close to the company. We’re still waiting to hear bak from our own sources with any additional info.

Update 2: BlackBerry has responded with a reaffirmation that they haven’t yet announced an official date, but T-Mobile UK still hasn’t retracted, removed or added more context to its tweet (update within the update: and now the T-Mobile UK tweet has been deleted):

We haven’t announced a date other than BBM for iOS and Android is coming this summer.