So before folks focus too much on the "white" in whiteboard thingy (ragebait). I had a quick break and glimpsed at the paper under discussion. The paper is a bit convoluted and is more in social science lingo, which certainly does not endear it to natural scientists. As such I really only skimmed it.
That being said, the whiteboard is not in there, because of the word white, it could have been any board, or a flip chart or similar. What the authors claimed is that in their observatory session certain persons were using the board as a dominance tool, to focus attention on themselves as opposed to a collaborative tool with equal access for everyone involved. They reframed it in a hierarchical system prevalent in white patriarchic societies. There is a bit of a stretch (IMO) that is not uncommon in social science papers in establishing these contexts, but it definitely reads different than saying whiteboards are racist.
If someone said that they either have not read the paper or are stretching context in an arguably similar or worse way as they are accusing the authors of.