There's nothing wrong with tunnels! Going through tunnels at speed on a woodie is great fun! I just feel from on offride perspective it would be more visually appealing without a tunnel from the top of the first drop to the very bottom. Either way these are just from the plans and this could change.
They are noise tunnels. Without them it's quite likely planning permission wouldn't have been granted.
Given how close SW8 will be to the boundary of the park they've had to make steps to reduce the amount of noise generated by the coaster hence the tunnels and magnetic lift hill.