A, B and C for sure at airports/planes. I've seen D - temperatures in day to day life (dr, dentist, massage, hair salons, etc.) but not in travel so far.
I recently traveled - actually took 6 flights. All of these items were used in airports, planes, etc, and I would not expect any less over the course of this next year. This IS the new normal and we need to get accustomed to if IF we will have a better future. I was please with the Duty of care and Safety of Delta throughout the process.