This could open up a world of insanity if turned into precedent. Granting constitutional rights to non-citizens on foreign soil?
It has nothing to do with the non-citizens' rights so much as the EO directly violating the constitution in nature by targeting a group of non-citizens based on their religion.
Well actually it does. What standing does the plaintiff have in this case? How can you infringe on freedom of religion for someone who is not a citizen and not on us soil? How can you extend equal protection to visa cancellations?
There's a million reasons you may not like the EO, but if it is ruled unconstitutional on the basis of religious discrimination it opens up a can of worms like we've never seen before in our legal system.
In that sense, you have a point, but note that the EO also targeted permanent residents with Green Cards, who are protected and afforded those rights.