Looks like the only reverse dep is sci-electronics/xoscope and it doesn't look to need the support for deprecated glade slot. I would then disable it to let us start cleaning that slot Thanks
+ 09 Jun 2015; Michael Weber <xmw@gentoo.org> gtkdatabox-0.9.2.0.ebuild: + Drop wrong dependency on glade:3 (bug 551288). +