If they're working on one, it will be released when they finish working on one. Software isn't like shoelaces - you can make so many per minute. Forecasting the release date of an app that's just about done is sometimes impossible. (T-Mobile gave a "will be released [the next day]" announcement once. That night, a developer playing with it at home found a major bug. The release was canceled and the update wasn't released for another 2 weeks.)
So even if they announce tomorrow that they're releasing the portrait mode, it may not be released for a few weeks (or even months - I once had a database bug that was caused by a single-letter-typo - that took 6 months to find - about 3 minutes to fix and recompile, but 6 months to find).
It's easier to forecast who's going to be elected US president in 2040 than to forecast when a particular piece of software will be complete. That's why we have so much bad software. When Marketing says it's the release date, it gets released - with all the bugs that haven't been fixed yet. Companies that don't let Marketing set release dates (like Google - we're on the 4th beta of Android P ... and if a major bug shows up, we'll have a 5th beta) usually release pretty good software.