Isn’t your son currently choosing which university to attend for his Bachelor’s degree?
A lot of things can change between now and when he might be ready enter the US job market.
The current “immigration ban” order was deliberately written to have minimal impact on corporate America. It doesn’t touch temporary work visas and it affects only a tiny minority of employment-based green cards (most of which are obtained via a process called adjustment of status, which will continue). It’s mostly affecting family-based immigration and the green card lottery, which are perceived to bring “lower-quality” immigrants into the country.
The country is facing so many other challenges right now that I don’t foresee any major changes to our immigration system before the next general election this November.
What the immigration situation will look like when your son might be ready to enter the US job market won’t depend on what the current government does, but the next one we elect, or maybe the one after that.