If it's a money issue, they could always adopt their past business model. M&B offered buy-in permanent beta access & the full game on release. If they offered alpha access at, say, 60% of the final release cost they'd get a huge cash boost right now. They could offer beta at a later stage for 80% of the full price, which is still a good deal for an anticipated game like this. If the final cost is $40 USD, that would make the alpha $24 USD and the beta $32 USD. With TW self-publishing again, they wouldn't have to give Paradox a cut of that. There are lots of hungry fans that would snatch it up in a heartbeat. They could even do a 70% alpha and 85% beta and still move a lot of copies.
Early access/buy-in testing isn't limited to indie start-ups, and most of the bad press surrounding early access comes from indie start-ups that fail. TW is a trusted developer with two successful titles backing them up. I think lots of people that wouldn't otherwise buy an early access title would do so from TW because it would seem safer.