Has it become harder for Chinese students to be accepted into graduate programs in the US?
US universities have always taken country of origin into account during admissions. I don't think there will be a major difference on the University side for admissions moving forward.
The visa situation is something else though. DHS is sitting on J1s, won't process H1Bs at all, but is still approving F1s and OPTs. This is likely to have a substantial chilling effect as it makes it much harder to do post completion training in the US.
I'm not sure they're going after china more than any other country - had a Singapore national just say forget it and walk away from a job offer over visa issues.