There is clearly a difference of opinion in the different reporting about what the school actually did. You did ask me to look up multiple independent sources.

The whole thing however looks like a terrible idea from the start and the "change" even worse. A school should not give day of absence to people based on gender, race or skin color, nor should a school support the idea to encourage people to stay away if that was what the "group of students" suggested. A school should do everything they can do in order to make students feel like they want to be at school, and doing social experiments where they encourage/permit students to not go to school (if that was what the original concept behind the walkout tradition) is a terrible idea. This is, as I mentioned earlier, why board of ethics exist.

The thing Evergreen State University should have done is do a public statement that all students regardless of race is welcome and wanted every single day, every week of the year. End of story, end of controversy, just a plain explicit message. No walk out, no white students opting to not go to school, just plain school where everyone is welcome. Then they would not have different political media platforms giving different narratives of what did or did not happen.