Now, imagine the same scenario, except what your previous employer said was true. But you sued them anyway.
In both cases, you have the ability to sue. In both cases, unless there is some very strong and obvious evidence against you, a judge and/or jury might take your side.
From the perspective of one of your former employers, it's just not worth the risk to give details about why someone was separated from a company.
For the sake of my argument, I was conjuring the scenario where companies give either positive recommendations or bare minimum ones.
Problem is, in many countries, it's not a fact until a court has made a judgement.
Bearing in mind that the accused employees are technically and legally innocent, you are introducing a few problems. First, the disadvantages of calling these people criminals:
1. They can (and probably will win) sue you for calling them a criminal.
2. The resulting news that a court found against you is a bigger problem. You called someone a criminal, they sued you for it and won. Now you have to deal with the fact that as far as the public goes, you just fired and shamed innocent people.
3. Finally, after the news gets out, all the employees who were laid off in the same round and with same accusations now have legal precedent to challenge your accusations of criminality. And due to precedent, they will almost surely win.
Now, the disadvantages of giving only their start/end dates and job title when called:
[uhh, I can't think of anything ...]
It all boils down to "there is some risk in badmouthing them" vs "there is literally no risk, 0% risk at all, is saying nothing about their behaviour".
Even if you think something is true, someone else might contest that, and ask a court to decide. Court battles are costly and time consuming.
IANAL, but basically it's not worth it. The company already has what they want: Not working with that employee. Anything past that is unnecessary risk.
"That person was fired because an investigation conducted by our company suggested they participated in sexual harassment."