So this is a bit counter to the news article's point, and apologies for linking to Reddit... but there has been a fairly hot post on the subreddit r/USCIS. A practicing immigration attorney was sharing some thoughts on how feasible the promises are https://www.reddit.com/r/USCIS/comments/1glflxy/so_what_now_an_immigration_attorney_perspective/. Some quotes:

IMO, no-- the economy makes way too much money from DACA folks. I do believe that they will dangle it like a carrot to appease right-wing voters. Major corporations employ DACAmented folks. The SSN from work permits have allowed more tax revenue to come in. Too much is at stake. Legally, the legal arguments at the courts surrounding DACA involve constitutional rights, which themselves aren't going anywhere anytime soon. It's honestly just a topic that is often talked about, but hardly understood by many.

I want to put this into perspective. There are 11 million undocumented immigrants in the US. Currently, DHS has about 92,000 officers, and ICE has about 21,000 officers. It is asinine to try to achieve this.

Let's say it actually does begin and people are getting rounded up. Guess what? Not all undocumented folks are just undocumented-- many have TPS, pending asylum applications, pending T/U Visas, and work permits (see my point regarding #1). Unless a migrant has an expedited removal (not likely), DHS/ICE still needs to process each deportee, assign them A#s, and follow basic procedures. If they don't? That's a very easy way to reverse a deportation order. It's the equivalent of convicting someone of murder using a confession made under a very obvious 4/5th amendment violation. Slam dunk case.

Oh, and you know who has to handle all of these deportation cases? Federal DHS attorneys. They're already overworked, and they tend to exercise discretion. If no discretion, the overworked ones tend to gloss over cases and provide weak arguments. Only major attention is paid to serious crimes. You'd be surprised the amount of times DHS attorneys have gotten my clients' names wrong or made procedurally embarrassing typos.

... assuming the administration still follows basic social contracts, that is. If the Trump administration actually uses the military to forcefully enforce mass deportations, then I feel the US is going to be fucked on so many different more levels... and there would be way more to worry than just the deportations