The way this stage approaches the climb means you have a 180 degree bend at the foot, so won’t carry any momentum into it. It makes a bike change pretty simple as you’re almost at a standstill anyway. The climb averages 10% so changing from a TT bike to a climbing bike is probably worthwhile.
You didn't really see it in the 2017 Worlds TT and I can't see it happening before a 1.8km climb either.