Thank you so much for your detailed response!
I have a couple of questions:

First of all what is the underlying cause of the delamination? Is it just an issue of age made worse by leaving it empty through the winter? Or is it completly caused by the cold weather and it really would've just lasted indefinitely had been left full throughout the winter? Also is it possible that there is water seeping through the concrete wall from the ground causing or contributing to the delamination?

As far as repairing it, being that most of this work would have to be done in-house and we don't have any expert advising us on the ground, it would seem to make sense to me that the best option would be to stabilize the problem , and once we're sure that we're on the right track investing in a full repair. What do you think about this plan?

Just to clarify your actual repair recommendations, you are suggesting that I first fill in the holes with patching concrete and then repainting. Furthermore I should tap out the entire pool finding delaminated spots. Once I do that what should I do, should I break off all the delaminated plaster and then patch them and repaint them?

Also I would like to ask you, I'm not sure I understand why eventually all the plaster would have to be scraped. Is it because the delamination would just continue and continue and I'll just have to keep on repairing it?

I guess this comes back to my original question, what is causing the denomination.
Once again your advice is much appreciated!