Put it like this, it won't be offered a decade from now.
We know. We've heard this rumor before. Heck, this writer has asked more than one top BMW executive this very question, only to be reassured the manual transmission is alive as long as there's enough demand, which mainly comes from the US. But not one of those executives could definitively tell us the manual will be around forever. That's because it won't be. According to Bimmerfile, BMW will be permanently ditching the manual over the next 2-6 years. And yes, this timeline also includes the US market.
Bimmerfile managed to get hold of a future product schedule for several redesigns of existing models and the six-speed manual, currently a no-cost option, is nowhere to be found. The demise begins in 2020 when the next 2 Series arrives. The ZF eight-speed automatic will likely be standard across the board for all 2 Series variants. And that includes the 2026 M2. Yes, it is a ways off, but Bimmerfile believes the next M2, M3, and M4, the latter two will arrive in 2020 or so, will be the last M cars to offer a manual. Chances are the '26 M2 will be developed on the same drivetrain as the M3 and M4, thus allowing to cut development costs. Tossing a manual option into the mix, even for just the M2, makes absolutely no financial sense.
Also looking ahead to 2026, the replacement for the soon to be revealed next-generation 3 Series (yes, we know it's far into the future) won't have a manual option at all. Nor will the 2027 4 Series. Even the 2019 3 Series will only offer a manual in non-M models and in the 330i four-cylinder variant. Call this a manual transmission phase out. It won't end abruptly, but it'll be gone for good in BMWs within a decade.