Are new projects supposed to be well successful today to pay bounty hunters their promised payment?
No, not a guarantee, the success rate of new projects is still low, it has not change AFAIK.
If they raise huge amount of money paying bounty hunters won't be a big problem, am I right ?
Of course it's not a problem, but unfortunately, there are projects that are still not paying bounty hunters, and you will be surprise that they declared to raise a big amount of money but failed to list the project in big exchange, If you know what I'm saying, these projects are shady and they'll never pay their bounty hunters or if they'll pay, no guarantee that the price of the reward is the same as the IEO price, mostly it's lower.