Yes, we do plan to spin down the builds of EOL'd Ubuntu platforms. we have not done this yet as we do not have that level of configuration built into the buildfarm. So we'll need to do some development to support that.
With respect to libgphoto2 this isn't an EOL issue. It appears that in Saucy only libgphoto2-6-dev was released to replace libgphoto2-2-dev but the decision was reverted in trusty. So to fix this we just need to update the rosdep rule.
Package: libgphoto2-6-dev
Priority: optional
Section: libdevel
Installed-Size: 11550
Architecture: amd64
Source: libgphoto2
Version: 2.5.2-0ubuntu5
Replaces: libgphoto2-2-dev
Depends: libgphoto2-6 (= 2.5.2-0ubuntu5), libexif-dev, libusb-1.0-0-dev, libc-dev, pkg-config
Conflicts: libgphoto2-2-dev
Filename: pool/main/libg/libgphoto2/libgphoto2-6-dev_2.5.2-0ubuntu5_amd64.deb
Size: 3340498
MD5sum: d57c9dc5d1d22c38edeec64902755179
SHA1: 6f1ad45da2c535f799268e13f9b7f81fcc6b151f
SHA256: 9974beae6a435a5678e24d8e02abfefe36097e8db9c009920ee5cd783f68f019
Description: gphoto2 digital camera library (development files)
Description-md5: 09f6d0ae3f118a398b90fb84845618e0
Origin: Ubuntu
Supported: 9m