Well, it would be good if they did, but they don't have to. They could just leave it to rot. While i understand this is not desirable, it does have one advantage, not taking development time from other things which may (or may not) be preferrable.
I mean, for those who want powerplay improving, then sure, its a priorirty, but there is probably a large majority of players who don't give two figs about powerplay and never will no matter what FD do with it, and if the proposal is make PP open only, that's a pretty significant part of the population who won't care about PP at all afterwards. So, if it came to (for example) a delay of space legs by 3 months while ED works on PP improvements, i'm sure there are many (a vast majority i daresay) who would be like "What the hell, FD! Forget PP! Get spacelegs out of the door quicker!"
Of course, this might be a good argument against a vote regarding PP
From what FD have told us, from what Paige, Zac, Sandro and others have said FD are keeping watch...its just making all the loose ends match up and we get some development.
The problem with this arguement is leaving Powerplay any longer though makes removal more preferable, because the 'system' has run its course without further change. FD developed the BGS which now outshines it, so its either got to evolve or go. FD have cold feet on Powerplay mainly because I think they underestimated the level of upkeep the feature needs, that it came at a time when internal visions were changing about the game, and that FD simply did not understand what Powerplay was for and what it now is.