Omg! Congrats! The fact that you received the golden email with the tracker still showing "not started" kinda gives me hope things will soon happen for me as well! Did you have any ghost updates during these 6 months?
Tracker generally seem to be lagging behind, GCKey even more so. Receiving email can be very independent of what you see in tracker or GCkey. In my case, tracker was updated 3 days after my PPR and GCKey was only updated when I got passports stamped.