I would definitely not want any growling on the album tbh. pig squealing maybe , nah just joking. I like Jonas' voice so much that Imo some harsh vocals will ruin it if they take a big role. If I want to hear some growling I just listen to BMD or DODS
On a somewhat serious note, maybe Anders will do some clean vocals. Jonas' needs no break, but it would be very interesting to hear Anders showing off his pipes as well.
Is SW actually producing? I'd like to know... I haven't heard anything remotely close to official, I just remember reading a rumbling about it a while back. I would love it if he produced! Doesn't matter if he doesn't though, still excited for the new album