Although this would undoubtedly help, BA would still need to employ more people to handle the volume of calls on weeks like this. The agent I spoke to on Friday to get my flight change, who was also outstanding in handling my call, said that they were staying on a few extra hours until midnight. It seems to me that BA hadn’t fully prepared for the strike announcement by having an army of people it could bring in at short notice to cope, probably because that costs money.
IMO this all comes back to penny pinching.