I believe Air Alderney were already committed with their own private charters on the day(s) when the disruption occurred, hence why they couldn't help out.
EDIT: Just seen this post on Air Alderney's
Facebook page:
Air Alderney Statement - Easter 2022
You would fully expect Air Alderney to be making much of the Easter weekends disruption, indeed many have stated ‘where are you Air Alderney’. In reply to these comments and others, we simply wish to make the following statement.
Air Alderney offered an aircraft on two occasions (Thursday and Good Friday) as it become clear the problem was not going to be rectified as soon as hoped. Our aircraft was flying to and from Alderney on charter commitments however, between these commitments our aircraft was available. We estimate around 70 + people per day could have been flown in and out of Alderney to Guernsey, that’s around 280 + people over the four days by our aircraft. The reports by the BBC and comments which state ‘no aircraft where available which can land on Alderney’s runway’ are not correct, one was available, and it managed to fly in and out of Alderney without any problems.
With all the disruption this Easter weekend with cancelled flights on Alderney's scheduled services, it’s not surprising to see one of Alderney States member (Mr Snowden) asking for a 'rethink on how air services are delivered to Alderney'. Unsurprisingly to many of you, Air Alderney welcomes such comments however, it’s difficult to see any of the proposals Mr Snowden has raised delivering a solution anytime soon. (Airport rebuild 5-7 years, or additional aircraft, the last ones cost £6M ) We all expect our politician’s to comment at such times but, Alderney needs States members which can suggest and deliver answers now, not in years to come…. The truth is the problems of this weekend could have been significantly reduced if there was ‘resilience’ within Alderneys Air Services. The good news is, this is available to Alderney now and could be operating within days without rebuilding the airport, a single shovel breaking ground or more expensive unaffordable aircraft being purchased. While Alderney burns its elected representatives are pointing finger at others whilst preventing an immediate solution.
Air Alderney will be giving its view on the airport options which have been presented to date including, one or two of its own very soon.