What actually happened on the three year journey?? Was there time shenanigans? I seem to remember rose and Dave on the meteor and jade and John on the ship but apparently that didn't happen?

In the post-retcon timeline Jade was alone for three years since post-retcon John and Davesprite died when Typheus destroyed Lowas. Typheus did this because he knew pre-retcon John would arrive in the new timeline with his Lowas. The only change for the meteor crew was Vriska was alive.