Mac OS 10.14 Mojave will be the last macOS release to support 32-bit apps, including 32-bit only frameworks such as QuickTime, Java 1.6, and Carbon.  Apple announced at 2018 WWDC that future macOS releases will be 64-bit only.

This somewhat clarifies Apple’s earlier vague statement that High Sierra would be the “last version of macOS to run 32-bit apps without compromise”.  Apparently Apple decided to give developers another year to get their apps updated to 64-bit.