Bernal knows today's final climb of Alpe di Mera very well. Not only he did a recon few months ago, but he also lived in that region for a couple of years so I suppose he rode up it many times. I couldn't find any information if Yates did any recon of it beforehand, like he did with Sega di Ala, which obviously helped him on that day. Meanwhile, Bernal rode Sega di Ala for the first time.
So today Yates won't have the same advantage over Bernal from knowing the climb, that had 2 days ago. On such demanding climbs it's a crucial knowledge that helps with the right pacing, choosing the right moment to attack or to limit the losses. I think it'll be super hard for Yates to gain any significant time today.
Reminds me of the interview with Buchmann a few days before his crash where he said that knowing a climb does not really help much in a race.