I find many sources online that say freezing is not recommended for fish pies. Mainly for the boiled egg reason. "boiled eggs do not freeze well and the whites tend to become rubbery and unpalatable once thawed, so it is not recommend freezing the pie with eggs in"
Simon
I haven't used boiled eggs and they freeze ok as I've had some already in fact it's enhances and infuses flavours better. I do leave them in the fridge before I freeze them. So I've had no issues