Yes it could be. You can trust anything in this space. Normally ieos are in big exchanges is very rare chance to be scams. But in mid and small exchange which ieos are offered can be scammed.
Is the ticket system IEO in big exchange can qualified as an IEO ? Since the one who get the coins is the one who has lot of balance and lot of luck.
I think the exclusivity of the coin make the price going high
Don't you even think if the main aim from exchange site use lottery system is to make sure IEO will put fairness as the main priority?
It's not about the exclusivity to the coin but some pumpers can load a few percents from the total amount that already offered on IEO. That's the main concern in this case.
People with a lot of balances don't mean that people can get in the ICO instantly but these people are only increasing its chance from getting more ticket.