No Warlock cooldowns directly affect each other in a greater amount when used one way than another. Blizzard finally made Warlock abilities (like Metamorphosis, Summon Doomguard/Infernal, etc.) to be dynamic with stat/damage updates, instead of snap-shotting your current stats upon cast.
So no, you can use any of those skills in any order, and it'll work out the same way. That also holds true with using your Demon Soul: Knowledge ability.