Sony Mobile has been careful not to overpromise on when the Android 6.0 Marshmallow will officially start to roll on Xperia handsets. Apart from the successful Concept for Android program, which has been successfully rolling the latest versions of Android 6.0 to Xperia Z3 and Z3 Compact participants, news on the official Marshmallow rollout has been quiet.
Sony has still not released any expected ETA, but last October Australian carrier Telstra indicated that a January 2016 launch looked likely. Now the same carrier has updated its software update page to confirm that Marshmallow for the Xperia Z4 Tablet “has been delayed” and they are currently waiting on Sony “to revise submission date”. Given the lack of official information right now, this is the best we can go on, but we’re still hopeful that the update will start to roll in the coming weeks.