I was under the impression that whatever criteria were used for the grants were met when the grants were made, so unless the institution has changed to violate those criteria, the grants should stand. Retroactive changing of the criteria should not affect them. As far as we've seen, the threat to defund colleges has been based on reinterpretation of ideas, often pretty vague, not on the colleges' conduct. The allegation seems to be that the government violated what Trump now believes the principles should have been, not that the colleges violated the principles that were applied by the government at the time.
Which is to say that I agree with Johnny Karate and Hercules56 on this one.