For me, it has felt like Jennifer has been part time in 6B. She has barely been in a lot of the episodes. I think that if this is true, which it may not be true at all, then it was something more like Jennifer said she would come back for a few episodes. I can’t imagine Jennifer agreeing to be available and yet get less money and less credit. The availability, i think, is Jennifer’s biggest issue. She wants to do other projects and so i can’t imagine her being willing to be available whenever they want for every episode even if it is less time like it has been in 6B. If she can work her other projects around doing Ouat then sure, but i would imagine it is Ouat that is going to have to work with her and not that she is going to continue to let Ouat control her time.
I think, for right now, i am going to assume that while there might be a little truth behind this, the wording in the tweet is incorrect.