Canned chicken is a staple on long naval deployments when freezer space is at a premium and underway resupply isn't possible. (Think submarine; running submerged and hidden for several months. The diet gets a bit gnarly after a few months, with egg powder and canned chicken!) I've also heard of canned chicken being used at forward Army/Marine deployments; not quite MRE territory, but the good old mess tent and trucked in everything.