Federal Unions are saying: "Don't Accept the Buyouts because there is no guarantee you will get the money at all"

The reason for this is that ONLY the Congress can actually authorize funds like this and what are the Chances of Congress authorizing these buyouts?

Likely at best 50-50 or less depending upon many different factors. So, if you take these government buyouts you might be doing what Twitter employees got when offered buyouts which was Nothing from Musk at all.

So, the buyouts most likely (at least for now) are at best Lies and at worst a complete swindle like happened to Musk's Twitter employees recently. 

Also, the person promising these buyouts has no Federal authority over any money at all to be paid in these buyouts, Musk.

Trump isn't really promising this, Musk is who has no authority whatsoever to grant these financial buyouts.

So, there is likely a 75% chance that you and your families will be left holding the empty bag with no money and be in a worse fix than now just like Twitter employees were left out in the cold too.