This reminds me of Elon Musk saying that endangered species could be raised on Mars, because… uh, yeah, they didn’t think it through very well. These people should know better, though. I don’t expect Elno to understand anything.
If the Earth is rendered uninhabitable, then this is a useless thing. The people who no longer exist from a civilization no longer capable of rocket flights wouldn’t be able to access it and even if they could (e.g. they already lived on some sort of Moon base), would no longer have any place to grow the things stored here. The very apocalypse this is banking against would make it impossible to make use of it. I can’t imagine any scenario in which this would actually be useful. As you point out, earthly seed vaults are useful under a variety of non-apocalyptic scenarios, on the other hand.
Which makes it extra nonsensical. For one, “terraforming” is basically fantasy bullshit, but also “we’ll need lots of plants and animals on Mars, so we’ll… store them on the Moon?”
After which I will reconstitute whole species from some frozen cells, and then use them to repopulate entire ecosystems that were damaged to the point where these organisms couldn’t exist there anymore (and we didn’t have the ability/will to keep the ecosystem from collapsing in the first place) Yeah, cool.