There’s many examples of government shutdowns where workers received back pay even when they didn’t work those hours.

So future administrations are likely to retroactively approve payments if it becomes a political issue. Honestly taking the buyout without an act of congress backing it is likely the more risky here unless you where already planning to leave which is likely why most people took it.

By law they have to be paid for the furloughed time in the case of a shutdown, since 2019. Previously, they were typically paid for that time whether they had to work through the shutdown or not but it was not guaranteed.

https://crsreports.congress.gov/product/pdf/IN/IN12251

Who's going to enforce that law?

That's a good question, perhaps it should be posed to the members of the so-called party of law and order.

The employees, suing in Federal court, since they have a clear and obvious loss to point to, they will have standing. Judges can either obey the law or not. If they don't obey the law, then we are much further along on the authoritarian spectrum then everyone thinks, but so far Musk has lost a lot of court cases and has several emergency injunctions against him doing anything.

Judges can write as many judgments as they want, but who's going to enforce those judgments? Only an executive branch that is interested in the rule of law is going to care about judgments.

Being the head of the executive branch only provides so much actual power here.

You need to replace lower level employees as Trump is trying, and at 1% adoption mostly failing to do.

That was a different situation because those people continue to be employees. The gov gave them back pay during shutdown because it wants them to continue to work after the shutdown (so services keep being rendered).

In this case, Trump/Musk don't want these workers back, so there's no political incentive or pressure to pay them. They can just not do so if it's "not funded by Congress" (usually there's fine print about this, at least there is in gov contracts, which are similar).

I recall there being some significant gaps, so these people had already returned to work.

But it’s not just about current workers, new administrations have handed out money to people for past issues years or sometimes decades after the fact. Just as an example the 1990 Radiation Exposure Compensation Act was about compensation for people exposed during the Cold War.

$50,000 to individuals residing or working "downwind" of the Nevada Test Site $75,000 for workers participating in atmospheric nuclear weapons tests $100,000 for uranium miners, millers, and ore transporters https://en.wikipedia.org/wiki/Radiation_Exposure_Compensatio...