Good spot. It used to be GPL licensed. How odd. If you goto the gitlab project at https://gitlab.com/inolen/redream it's basically just a support forum. Anyone got any more details on this? Is this an attempt to monitise the work?
Edit: I see you can upgrade to "premium" but it's a one-time fee of only $5 so money can't be the motivation here. Same at https://gitlab.com/inolen/redream/issues/957 An acknowledgment of the situation is at https://gitlab.com/inolen/redream/issues/543#note_91625154 but sadly no explanation.