If they only had a pre-ico then it wouldn't be a pre-ico because it would not precede the ICO. Thus the pre-ICO would become the ICO itself.
Yes, That what I want to say.
Term Pre-ICO is the combination of 2 words PRE(before Time) and ICO. So basic agenda of Pre ICO is to provide opportunity to early investors to gain more profits as a reward for trusting their project and taking more risk. Pre-ICO generally provide bonus coin or offer coins at cheaper rate than in Main ICO.