It's a progression I agree but IMO a natural one. With the Lich King dead both she and the rest of the Forsaken had a choice- return to true death or embrace undeath as a legitimate mode of existence and carry on. If she contuned to embrace the "slaves to this torment" mentality then the former was the only real option. However by accepting the Val'kyr and deciding to return to unlife she clearly decided that unlife was better than no life. Unlike her raising by Arthas, this time she chose undeath so it makes no sense for her to continue despising a condition she has now freely embraced.
Also there were always factions among the undead that embraced their new state, the Cult of the Forgotten Shadow perhaps being the most famous. It makes sense that the longer the Forsaken remain in unlife the more they embrace it- it's probobly the only mode of existence many of them can properly remember by now. Whether this is wrong depends on how seriously one takes the Void=evil and light=good shtick- just because it's an existence predicated on dark magic and is opposed by the light doesn't mean it's not a legitimate mode of existence for those who embrace it.
I agree though that freeing Stormwind from its humanity sounds weird though- I'm eager to read what exactly that means,.