There is one possible time pressure involved, which is that libsystemd dropped the liblzma dependency

Absolutely no intelligence agency would look at a successful compromise where they have a highly positioned agent in an organization like this, and burn them trying to rush an under-developed exploit in that would then become not useful almost immediately (because the liblzma dependency would be dropped next distro upgrade cycle).

If you had a human-asset with decision making authority and trust in place, then as funded organization with regular working hours, you'd simply can the project and start prototyping new potential uses.

No true Scotsman

Might a time-sensitive high-priority goal override such reasoning? For example, the US presidential election is coming up. Making it into Ubuntu LTS could be worth the risk if valuable government targets are running that.

Jia Tan tried to get his backdoored XZ into Ubuntu 24.04 just before the freeze, so that makes sense. Now is about the right time to get it into Fedora if he wants to backdoor RHEL 10, too.

But I don't think valuable government targets are in any hurry to upgrade. I wouldn't expect widespread adoption of 24.04, even in the private sector, until well after the U.S. election.

By the next election, though, everyone will be running it.

Edit: According to another comment [1], there would only have been a short window of vulnerability during which this attack would have worked, due to changes in systemd. This might have increased pressure on the attacker to act quickly.

[1] https://news.ycombinator.com/item?id=39881465

Presumably this intelligence agency have multiple such initiatives and can afford to burn one to achieve a goal.

On the other hand, this was a two year long con..