Calling hair dressers. New school who are use to olaplex

I just recently cut a lot of hair off about 6 inches and got a ton of layers. My hair is dark brown right now. I made an apt with the hair dresser for 2 weeks from now to dye it. We’re going for 2 treatments spaced out using opalex it might take more which is fine but I’m aiming for half brown half blonde. Was it a good idea to cut all that hair off before? Should I have waited until after dying it? Or does it not really matter? I wanted it cut anyway so that doesn’t change that it’s shorter now. I’m just wondering if the damage will need me to take even more off. The lady is experienced and has taken people from dark to light in a couple sessions so she knows what she’s doing. I’m just wondering if it’s smarter to cut before dying after dying if it doesn’t matter or if you should cut before and after anyway. Here’s some pics of my color and what we’re aiming for at the place.