The patch was successfully backported and merged today.
Sadly we find that this didn't totally solve the problems because is seems the "old" DOM is still cached in varnish.
Varnish caches have a TTL of 24 hours so most stuff should be fixed in 1day or less (could be very worse case 4 days for odd edge effects where each page is a stale as possible without being ejected from each layer).
I think we need to figure out a way to prevent this happening again but for now I think we can let this occurrence sort itself.
@Lydia_Pintscher is that ok for you?