From what I have been able to determine it looks like libwayland-egl1-mesa-lts-xenial isn't depended on in the same way libwayland-egl1-mesa-lts-utopic was.
bdmurray@upgrade-trusty-amd64:~$ apt-cache rdepends libwayland-egl1-mesa-lts-xenial libwayland-egl1-mesa-lts-xenial Reverse Depends: libwayland-egl1-mesa-lts-xenial:i386 libwayland-egl1-mesa-lts-xenial:i386 libegl1-mesa-dev-lts-xenial libegl1-mesa-dev bdmurray@upgrade-trusty-amd64:~$ apt-cache rdepends libwayland-egl1-mesa-lts-utopic libwayland-egl1-mesa-lts-utopic Reverse Depends: libwayland-egl1-mesa-lts-utopic:i386 libwayland-egl1-mesa-lts-utopic:i386 libwayland-egl1-mesa-lts-utopic-dbg libegl1-mesa-drivers-lts-utopic
From what I have been able to determine it looks like libwayland- egl1-mesa- lts-xenial isn't depended on in the same way libwayland- egl1-mesa- lts-utopic was.
bdmurray@ upgrade- trusty- amd64:~ $ apt-cache rdepends libwayland- egl1-mesa- lts-xenial egl1-mesa- lts-xenial egl1-mesa- lts-xenial: i386 egl1-mesa- lts-xenial: i386 mesa-dev- lts-xenial upgrade- trusty- amd64:~ $ apt-cache rdepends libwayland- egl1-mesa- lts-utopic egl1-mesa- lts-utopic egl1-mesa- lts-utopic: i386 egl1-mesa- lts-utopic: i386 egl1-mesa- lts-utopic- dbg mesa-drivers- lts-utopic
libwayland-
Reverse Depends:
libwayland-
libwayland-
libegl1-
libegl1-mesa-dev
bdmurray@
libwayland-
Reverse Depends:
libwayland-
libwayland-
libwayland-
libegl1-