You "shouldn't" lose any progress in this update! This update we didn't do much in the way of changes that effect the saved data. But can't say for 100% certainty though.
I can say that NEXT update after this one, you will most likely lose progress as one of the last few systems that we need to completely overhaul, is the save system.
But, when I create the new system, I'll try and create a tool that will allow us to convert the data to the new one. Just can' t make promises on that.