Well, for previous bundles they said this:

The key provided for this product, needs to be registered via http://www.jastusa.com/ Simply use the key in the Game Code section to unlock the game
Game download is DRM-Free

Steins;Gate is published on Steam by Mages themselves, JAST has no way to get the keys, as Mages specifically wanted to publish it on Steam by themselves. Besides, it's a pretty prized possession of Mages, they would not sell it for cheap.

But as always, being Japanese publisher, they're so stupid beyond reasoning. Steins;Gate on Steam is a total disaster from QA perspective.

Yes, that is exactly what it means. Downloads will be via JAST USA, not Groupees.

The jast-usa activation codes show up in your Groupees library, same as Steam/itch.io/etc codes do. You then go to the jast-usa website and activate them to your jast-usa account, at which point they function in a manner a bit similar to GOG games, in that you can download them at any time (screenshot of the top of my Jast account downloads section below):

View attached image.

so you can download them or re-download them at anytime?

Yes.

do i need a jast-usa account before i buy the bundle?

No.

Not bad! xD And yeah, with Steins Gate in the last Jast bundle, I find it a better bundle, and more justified with the price tag. But there are still some interesting titles in this one when I briefly looked through them! ^^'

:O The groupees page, or Jast' site? VPN ftw then?

The latter. My gov do block JAST's site as well. They think it's a porn site or something.

the "Jast" site... ( ͡° ͜ʖ ͡°)
Groupees is fine..

Yes or proxy, i just checking what i got from this bundle ( ͡° ͜ʖ ͡°)