This wouldn’t be rounding people up based on their ethnicity.

• It would not be rounding people up
• It would not be based on ethnicity

Instead:

• It would be applying a particular dispatch when people encounter the legal system
• It would be based on legal status

So in the same way that a government could have a policy like

IF you are stopped while driving drunk THEN you will be put in a jail cell for drunk people

this would be a policy like

IF you are brought into custody and we determine you’re here illegally THEN we will deport you

So no, this isn’t in any way like rounding people up (ie performing a dragnet across all of society to ferret people out) based on ethnicity. Like, at all.