Created attachment 517700 [details, diff] A patch that fixes the problem for 8.0.1298 gvim should to work as a command line vim too which means /usr/bin/vim symlink should be installed (/usr/bin/vi is handled by eselect and is working as expected). Latest stable version of the ebuild (8.0.1298) doesn't install the symlink. Accordingly to the wiki[1] this is supposed to work, maybe it was changed accidentally. 1. https://wiki.gentoo.org/wiki/Vim#Gvim
This would collide with app-editors/vim and doesn't make sense to do. If you want vim available just install it in addition to gvim.