I386 architecture will be dropped starting with Ubuntu 19.10

Last year, the Ubuntu developer community considered the question of whether to continue carrying forward the i386 architecture in the Ubuntu archive for future releases. The discussion at the time was inconclusive, but in light of the strong possibility that we might not include i386 as a release architecture in 20.04 LTS, we took the proactive step to disable upgrades from 18.04 to 18.10 for i386 systems, to avoid accidentally stranding users on an interim release with 9 months of support instead of letting them continue to run Ubuntu 18.04 LTS with its 5 years of standard support. Consequently, i386 will not be included as an architecture for the 19.10 release, and we will shortly begin the process of disabling it for the eoan series across Ubuntu infrastructure.

Source: discourse.ubuntu.com