Really, this is a myth. Both OLPFs and IR filters are cheap to produce. In fact I don't see why an OLPF's function can't be reproduced digitally during demosaicing. Cannon, Sony and Alexas produce moire same as every camera. The only thing that varies is the size of the detail. That said, I too was shocked by Epic Light's footage. It seems that 12K "interacts" with very small patterns such as a cotton shirt's fabric. This could be a fatal flaw for 12K.
There are cameras like that. They just aren't BM. I personally will dumb the company if it goes that way.