I'm not sure if they were listening to their player base or just listening to the money. With Alchemy being unpopular and requiring extra art + dev time I can't imagine they had any incentive to keep it going if no one was buying in.
I have to imagine once Pioneer gets the full card pool play may go up a bit?
Are there any major decks that are actually missing cards? I figured that they had added pretty much all tournament-relevant cards. But I think the bigger thing for online Pioneer would be more support for paper Pioneer to spur interest in the format.