Yes, I have some boxes and cans of 'survival seeds.' (I use the term generically, not referring to any brand) I sure hope I never need to use them. If you have some, look at the packages. What do you see? A small number of warm season vegies with a small number of seeds in each. IF you are successful with those crops, you have some food that can be canned or dried to help in the coming winter. Is your assortment enough to sustain life? Probably not.
My seeds ignore other growing seasons and conditions, which could be critical in a long duration emergency. For those who don't live in the northernmost states, your other growing seasons can be productive if you have the right seeds stored.
For us in the high desert, we can plant cool season crops outdoors in March. These crops bring fresh greens and the accompanying vitamins and minerals to the table. Another planting season starts after the monsoon and as late as the first of October. Root crops are a bonus item during this time. Rutabaga , turnip and beet greens are also a great addition to salads and soups. Leaves can be harvested sparingly without hurting the tubers forming below. The tubers can be harvested in late spring, adding carbohydrates to your diet. We also plant parsnips at this time, but don't see the final product for almost a year.
Winter is a growing season for most. All you need are some trays, a glass bottle with some door screen and a window or grow light. Sprouts can be grown with minimal light and water. Add a tray of soil to the same seeds and let them grow a few days longer with light and you have Microgreens. Both will add needed nutrients to a winter diet of canned and dried food.
I set aside mixed seeds for both sprouting and microgreens, along with more root vegie seeds for my emergency garden. Otherwise, if your long-term emergency doesn't conveniently start at the beginning of your warm growing season, you could be out of luck for months.
My favorite source of both root vegies and mixes for microgreens and sprouting is Johnny's Selected Seeds.