yes its perfectly fine, I've had plants do this in week 10 and surprise the shit out of me lol. I call it their last wind, or final show
Let these new white hairs phase out and turn into the brown or red or whatever, and then watch those trichs. closely to see when its time to start the flush and cut.
Being 8 weeks in, id go 1 more week, and start flushing with molasses water until the harvest. Molasses helps give the buds a fine taste, also check out "Gravity" from Humboldt county, it makes more dense and heavy buds