What if features X, Y, and Z needed in < 6 months each are 2x harder to code because of the planning of feature B that has a 90% chance of being needed after them? You potentially "saved" time by doing feature B but depending upon the total time to code feature X, Y, and Z, 10% of the extra difficulty in features X Y and Z may still outstrip 90% of the time saved in feature B.
Nevermind that as feature B goes unused for 6 months bugs and incompatibilities may creep in. Eventually what you wrote for feature B may be mostly useless when you finally get around to actually needing it. I have had this happen on projects before.
I agree. Projects should not be scheduled in isolation. Delay may be a great idea, or a terrible idea. Sometimes prediction is easy, sometimes it is not. Trying to oversimplify the decision making is a mistake.
What if features X, Y, and Z needed in < 6 months each are 2x harder to code because of the planning of feature B that has a 90% chance of being needed after them? You potentially "saved" time by doing feature B but depending upon the total time to code feature X, Y, and Z, 10% of the extra difficulty in features X Y and Z may still outstrip 90% of the time saved in feature B.
Nevermind that as feature B goes unused for 6 months bugs and incompatibilities may creep in. Eventually what you wrote for feature B may be mostly useless when you finally get around to actually needing it. I have had this happen on projects before.