DAZN probably gambled that Fight Night cards were bringing in punters to Sky when in truth it was probably punters from other sports and boxing lost the money quite often. Within the overall Sky Sports "channel" offering where they have to stay on air 24/7, they have a lot of filler content and undoubtedly, 6 undercard fights ticked that box. Streaming services work on different economics and now they've found that out.
That will improve sales of Event dramatically even with OTT price. Pubs with Virgin will pay that no problem.