It helps to put all family members on the I-526 because it is more difficult to add family members later. Even if your husband doesn't want to obtain his conditional permanent residency initially, having the option to is better than trying to add him later. At that time, you would probably need a marriage certificate. Having your husband join you when you come to the U.S. or later should not affect your conditional permanent residency.
It is not required to include your husband in your EB-5 petition. However, your marital status will be asked in the application and it must be answer truthfully. Providing a marriage certificate may be required. Once documented satisfactorily, your marriage should not come into question.
The EB-5 rules allow you to be the EB-5 investor and you and your children can apply for the conditional permanent residency.your spouse may stay in the home country to take care of business affairs and travel temporarily to the U.S. During the time of your conditional permanent residency. When you file your petition to remove the conditions of your conditional permanent residency before the two year anniversary of the CPR, you may include your husbands name in the petition and he will obtain with you, the unconditional permanent residency.