What are the tax liabilities on the foreign assets of the EB-5 investors?

It is advisable for you to seek the services of an international tax attorney and/or an international tax CPA to provide you an analysis and direction on pre-immigration tax planning.

EB-5 investors who have landed as immigrants are taxable like all other U.S. citizens generally speaking. There are tax treaties that may impact some residents. Existing assets in the U.S. or elsewhere are not exempt so pre-immigration tax planning is important.

Once you become a permanent resident, all revenues you earn from both within and outside the U.S. are taxable.

Yes. Under the IRS regulations, as a U.S. person, you are required to report all of your assets and earned income around the world. I suggest consulting with an experienced attorney regarding the details and necessary reporting and compliance of these IRS regulations.

Permanent residents are required to file taxes on their worldwide income. You should consult an international tax attorney to advise on how any tax treaty may help and what must be declared that was acquired prior to permanent residency.

U.S. permanent residents, regardless of how such status was obtained, are taxed on global income.

This would be better addressed by a tax attorney or a tax specialist. My understanding is that there are definite tax liabilities to worldwide income once you become a permanent resident.