my 2 cents:
XanderF says repeatedly that subscription plans are a windfall for publishers--this is wholeheartedly not true if you are at all familiar with the upkeep of IT infrastructure. It is expensive, to put it mildly, to maintain a server farm. A niche market, as sub games generally are, with a small number of players, would be nothing more than a horrid money sink. It would float for two, maybe three months before the publisher tanked--and that's assuming everyone who played it LIKED it.
I don't think this one is in the cards soon, unfortunately.
