Yes, when the WB turned to the CW, Berlanti realized that the CW wanted a certain flavor so he tried to temporarily fit the mold if it meant getting a season 5. He sort of winked to the fanbase in interviews to trust him. Apparently the three things that were going to take place:

1. Madison, the one that never went away, was returning to come back and talk to Ephram about something baby related. That beautiful Ephram/Amy Ferris Wheel scene? Never would have taken place. Amy would have been standing there like a fool while Ephram dealt with Madison. You can only imagine how the vast majority of the fanbase who already hated Madison would have reacted to that.

2. Ephram/Hannah would explore something romantically. Apparently it was going to be very short lived, just like the stupid Madison situation.

3. Nina was going to become pregnant with Jake's baby and a triangle between Jake/Nina/Andy would have developed. Yes, unreal, I know. This is the one that had the potential to last longer than the first two.