The first question you ask is already covered well in other discussion threads.
The second question I don't have an answer to. But that's the problem with trying to have productive conversations about a broad statement from a student group instead of discussing current and proposed concrete policies/policy proposals. In general, unless there's a concrete policy proposal on the table, we should tend to assume the best of people and avoid conjuring up Orwellian nightmares out of vague statements.
The article mangles two concepts:
1) Trigger Warnings
2) Safe Spaces
Both of these are being misused in some universities. Providing a warning to vulnerable people so that they can keep themself safe is fair enough. But some people point to the safe space policy and suggest that the trigger warning is not sufficient and that the material should not be taught.
Is that really a reasonable request in a literature class? Does the same apply to any traumatic event and any field of study -- for example, if a medical student was robbed at knifepoint, should he be given advance warning about seeing blood or cut skin...?
The quoted passage specifically mentions "people of color or students from a low-income background" in addition to survivors. How is that meant to be interpreted? What kind of writing do poor students need to be protected against?