I just synced the portage tree and seen that sys-libs/ncurses-6.0:0 has been removed, leaving only version 5.9:5 and 6.1:0. But 6.1:0 is affected by many showstopper bugs (see #652080), so I have it masked on my system until the packages I use work with it. Most packages depend on :0, so 5.9 is of little use. Please revert the deletion of ncurses-6.0 until 6.1 is in better shape.
our focus is on fixing the bugs. honestly, we could leave this bug open and just sit on it (i.e. do nothing) and then punt it once all the bugs in 6.1 have been resolved adequately, or just be up front in that we're not planning on re-adding it, especially given the security issues in ncurses-6.0: - bug 624644 - bug 625830 - bug 629276 - bug 639706