"I wouldn't doubt" is not anywhere near claiming that any or all did. Just my own suspicion and could very well be wrong.
With the propensity of BLM/antifa types using fire and flammables on public, private, and inhabited buildings, it wouldn't surprise me, if some of the arsons in these forest/brush fires in Oregon/Washington were of similar ilk.
That's looking not the case, but we still have dozens of fires highly likely of arson, with no suspects yet.
Most could just be pyro's taking advantage of high fire risk conditions, like what happens every late summer/early fall dry santa ana type conditions.
This guy covers a lot of BLM agenda ground in less than 1 and 1/2 minutes......