It's a rough decision for the individual athletes, considering games are every four years.
And if you start gatekeeping on countries being in internal or external conflicts and committing major human rights violations, there'll be lots of politics involved, wiping away even appearance of fairness.
As for the ceremony, there's no problem as long as there are no other neutral athletes than these. If there is even one, who then is included in the ceremony, that's more problematic.