Disney buying Lucasfilm may have been good for Lucasfilm as a company, but there were some controversial decisions made, such as the creation of a two-canon system, Disney and Legends. Most Expanded Universe content released before the decision was announced in 2014 was tossed aside into the Legends canon, which is essentially locked from further additions. Some "Legends" material is still in print, and others are out of print, but copies still circulate in the secondhand market, so it's not too big a deal for them. But some content was released via the Internet, and some of that content was exclusive to the paid subscription service Hyperspace. Several short stories were released exclusively through Hyperspace, and while I've seen many of them posted elsewhere (torrents, most of which are dead, Russian fansites, etc) some I was unable to find.
Disney eliminated a lot of stuff from the site when they took over.
There is also non-Hyperspace content, like videos that were available streaming in the last couple years before the buyout. For example, the commercial for the book Vector Prime. While this video is on YouTube, it originates from a recording made when it originally aired back in 1999, so the quality isn't good. Presumably, the StarWars.com version would be higher quality. The Wayback Machine can't archive these videos, because they're streamed. It also can't archive Hyperspace content because it requires logging in to access it.
Do you think there's any chance of recovering this stuff?
The Star Wars Wikia, "Wookiepedia" did record a lot of the information that was removed from the official site, though mostly the information on the content that was removed, as the direct content may be indefinitely, if not permanentaly lost.