So, the plot thickens… I’ve just completed Paris and did indeed unlock the shirt! Yay! 
Now, I’ve also noticed that when in completed the Zwift Run Festival 10k, I unlocked the marathon distance shirt instead 
I’ll feedback after Innsbruck on Friday…
Yes, I re-tried Innsbruck on Sunday and I got the UA shoes.
Edit: same for the white shirt but I wonder: is that shirt for the marathon distance (which I didn’t run) or the one we are supposed to unlock on December
I did 1,2,3,4,5 with no unlocks, then 2,5 both with unlock.
It might be a bug or it could be that the events were set up without the unlocks coded in, only added later on?
The white shirt has 26.2 on the back for the marathon and the 10k was in fact a black shirt
I think Zwift just want us to Run On! Hopefully I’ll unlock the shoes on Friday’s Innsbruck run
In the interests of science I’ve just set the treadmill off to do stage 2 - Paris.
Upon completion I received the reward.
I suspect it’s been fixed but does appear you need to do the stages again