Ubuntu Server 18.04 LTS Dropping 32-Bit/i386 Support
With no objections having been raised over a comment period the past nearly two months on the Ubuntu Server mailing list, Josh Powers of Canonical has issued the go-ahead to do away with the Ubuntu Server i386 daily images and the subsequent final Bionic Beaver release.
This change is just affecting the ubuntu-server i386 release while there will continue to be the x86 32-bit mini ISO image, Debian Installer image, and the i386 package archive will continue to exist. So for those running Ubuntu Server x86_64 you can still install i386 packages if needed, but the official Ubuntu Server image on the x86 front will be just x86_64.
Confirmation on ubuntu-release. In the unlikely event you still are using an i386 server, Ubuntu 16.04 LTS continues to be offered.