Correct, they can happily take a tourist visa in any country especially in developing country and get the procedure done. There are also medical tourist visa, which are famous in countries like Turkey, India, Thailand, etc for some special procedures. 

It is relativity cheaper than US, so most probably a new medical tourist agencies might be popping up like mushrooms all over US, I guess. That's a good entrepreneurship opportunity. 

But still poor people who are not employed by these big corporations or teen pregnancies in a poor family cannot circumvent the law by going overseas, they are the most affected. Software engineer in Google or Amazon would have already figured out a way for abortion or smart enough to even avoid it but again the poor and innocent people are the target here and they form the big majority and this ban will affect them pretty badly.