These packages make use of gtk3 useflag which indicates that there are issues of migration to gtk+:3.
Gtk3 and similar useflags should be avoided.
Adding to tracker. Please have a look.
Plans to migrate to GTK3+?
Lubuntu - Plans a migration to GTK3, but LXDE is not yet fully ported to GTK+. So a full GTK+ 3 environment will take some time.