Again you are confusing due process with the requirements of a criminal trial. A process that does not allow the parties to interrogate each other directly are still appropriate in many other situations.
So? New rules don't say accused gets to cross-examine accuser. Fine to require a third party lawyer or other assistant to accused to do it instead while he's out of the room. So what's your objection?
More generally, read Emily Yoffe's series at The Atlantic if you want a fairly non-partisan (if anything she's more left-wing, used to be at Slate) view of the problems with the college investigation/inquisition system.
Just from memory of what I've read, there have been lawsuits and decisions reached over such matters as:
1. Third party complained, both adult participants in sex said it was consensual, but she was disbelieved and he was kicked out;
2. In front of witnesses (both male and female) in her room to which she'd invited a male, woman gave him blowjob, then he was kicked out after she complained because when she started performing oral sex he didn't stop her and confirm she consented to perform oral sex on him (which she'd started to do without getting explicit consent from him?);
3. Many instances of male complainants not being treated seriously compared to female complainants, especially if woman were first to complain.
Re the ACLU specifically, they used to be about protecting people including the accused, insisting on rights of free speech and due process for neo-nazis, KKK, terrorists, murderers, and yes, rapists. Regardless of whether they or the government at the time were left or right. If now they are saying, hey, wait, if you're accused of sexual assault the rights of the accuser far, far outweigh the rights of the accused, well that may be a coherent view that any number of organizations might support, though many would disagree. But it's not a stance the ACLU should have taken, over time they've morphed from anti-government to anti-right-wing/conservative/Republican. I mean, any number of justices including Gorsuch (recently agreeing with Sotomayor in dissent to denial of granting leave to appeal), Thomas, and the late Scalia, have on various issues been pro-civil liberties. And contrariwise, left-wing justices and politicians generally have been anti-civil liberties on a number of issues. But the ACLU's new stance seems to be, it's okay to be a progressive oppressor.