I'm excited to read it, but just reading the introduction there are a couple of warning signs.
First, the contention that "Wobblies liked to portray themselves as carefree, wandering troubadours." I have not read extensively their public materials of the day, but certainly my impression is committed organizers seeking the overthrow of capitalism ("The working class and the employing class have nothing in common ... Between these two classes a struggle must go on until the workers of the world organize as a class, take possession of the means of production, abolish the wage system, and live in harmony with the Earth.") The Preamble to the IWW Constitution isn't subtle.
Second, the book is based on (heretofore hidden from public view) "documents seized from IWW halls that were presented as evidence by the prosecution" in a 1918 trial, it is implied that this makes it possible to "provide a complete, balanced picture of the union." Certainly it can help provide a more well-rounded view, and Chester is very clear about the provenance of his source material and i'm not doubting the history will be accurate, but i'm surprised there is not up-front recognition that the documents he will be drawing on were selected by the prosecution to show the IWW in the worst light possible.
Given the scope of the Bureau of Investigation's abhorrent raids across the country in 1917, it's a bit analogous to what the government can mine today for incriminating evidence from almost anyone's private e-mail and social media activity. While the IWW's public documents would one hopes present the union as it wants to be seen, it does not follow that what the government presented for evidence reveals "the union as it really was", even a glimpse.
Especially since the government chose to destroy all the material stolen from the IWW, so that all that survives is the trial transcript, we should be skeptical of what the surely biased hand-picked evidence portrays.
I hope there is or will be found correspondence not seized by the government and kept by radical groups or passed down in families, which could help round out the story further, but given that any such materials were shown to literally be used as evidence against people, it's not surprising that it might have been destroyed too.
Such is history under government repression.