Of course they should have been expected. The whole point of protests about "The Wall" was that a lot of people were being kept out, wasn't it? I mean, if only a handful of people were being victimized by not being allowed to cross the border a few NGOs and charities could have coped with them and we wouldn't have seen the appalling news coverage on either side of the border.
Changing US immigration policy doesn't change the conditions in any third world countries.
In the long run, though, we need to gamble on letting people in. The birthrate of US citizens dropped to 1.7 in 2019. Without an influx of population we'll end up with the problems of the sclerotic Europeans (if we're lucky) or the belligerent, male-biased one-child Chinese (if we're unlucky)