In my experience, once you get to true leaf stage, you're gonna be OK.
I do experience a bit more failure to get there with old seed; this isn't scientific but it's like the seed had enough energy to stick up a stem, but the root radicle faltered, or it couldn't shed the seed-coat.
We see this with fairly fresh seed, too, but it seems it increases with age.
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a day without fresh homegrown tomatoes is like... ...sigh
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