"Main reason Cowan is out is that his 50% co-owner has dropped out, I think. "
Not sure if that's an entirely correct way of putting it.
That fact that Ruffy wrote the letter, signalled a hopeful return in the future and signed off as "Co-Owner" suggests he is still 49% owner of the club.
However, I do suspect that he said to Cowan "This reform is stuffed, if you want to play this season you can pay for it, but I want to wait for proper change."
That's different to "dropping out", because if every team has the season off, which now looks likely, Ruffy and the Dragons are now in the same boat as everyone else.