Looking at flight options in March - arriving from the US on BA with an onward BA connection to a long-haul African destination (ACC) that is being moved from LHR to LGW on my travel date. Any help on the following questions would be much appreciated:

1. Future is uncertain, but given current UK rules, can Americans even make an onward connection at a different airport today?
2. Anyone care to make a prediction on how things might evolve be in March?
3. Why move ACC to LGW from LHR? I thought BA was consolidating at LHR. Should I just book my flight thinking that they will cancel the LGW move.