??? Your argument is upside down
The vast majority of 'bad labour practices' in the US stem from employment of illegal aliens.
Consider if those migrants were 'released from detention' they'd be employed illegally somewhere at sub-legal wages, sub-legal conditions, no unions, no complaints, no healthcare etc. etc..
Companies employ illegal labour largely because they can cheat on a variety of labour practices not because 'they can't find the talent'.
This creates a toxic effect whereby those trying to 'play by the rules' can be put out of business by lower margin competitors and are forced into to doing this. There are many jobs that Americans would in fact do if wages and conditions were above bar.
The primary driver of illegal migrant is jobs - when the economy booms, many more people enter illegally. When it's rough, there's a downturn.
It would be much more simple and humane to simply go after the employment of illegal aliens on the basis of humanitarian grounds alone and there's ample ways to do this.
FYI this likely would not affect the migrant of true refugees as much, ergo, you have a border system a little more focused on those in need, and less focused on economic migrants.
GitHub is a large business in a fairly politically secular area (software) - they should be able to support anything the US government does aside from possibly weapon systems or military activities. The place for employees to get upset is at the ballot box, protest etc. etc..