A cut that contradicts earlier reports
In the weeks before WWDC, numerous sources had reported that iOS 27 would maintain compatibility with iPhone 11, extending support to the broadest user base in iOS history. That reconstruction proved inaccurate. Tom's Guide, in its post-keynote summary, confirms that Apple officially drew the compatibility line at iPhone 12, excluding iPhone 11 and the 2020 iPhone SE.
Why iPhone 12
The jump has technical logic: iPhone 12 was the first model to adopt the A14 Bionic chip, built on 5 nanometers, with a significantly more capable fourth-generation Neural Engine compared to iPhone 11's A13. Some system functions introduced in iOS 27 — particularly those tied to local language model processing and enhanced animations — require resources that the A13 cannot reliably provide.
Who is left out
The second-generation iPhone SE, released in 2020 with an A13 chip, shares iPhone 11's fate. Users of these models can continue to use iOS 26, which Apple maintains with security updates for a limited period. The exclusion is less brutal than it appears in numerical terms: iPhone 12 has over four years of guaranteed support behind it, a longer cycle than the industry average.