What major changes will the new rules bring once they become effective on November 21?

Sure. The long-awaited increase for EB-5 will finally be taking place. USCIS published this news on its website last month. For applications submitted after November 21, projects in urban areas such as New York, Los Angeles, and Miami will no longer be treated as a Targeted Employment Area (TEA). The news was also published in the Federal Register.
To summarize:
As of the effective date of the final rule, the standard minimum investment level will increase from $1 million to $1.8 million, the first increase since 1990, to account for inflation. The rule also keeps the 50% minimum investment differential between a TEA and a non-TEA, thereby increasing the minimum investment amount in a TEA from $500,000 to $900,000. The final rule also provides that the minimum investment amounts will automatically adjust for inflation every five years. The final rule outlines changes to the EB-5 program to address gerrymandering of high-unemployment areas (which means deliberately manipulating the boundaries of an electoral constituency). Urban areas such as New York, Los Angeles, and Miami will no longer be treated as a TEA. The rule revises regulations to make clear that certain derivative family members who are lawful permanent residents must independently file to remove conditions on their permanent residence. The requirement would not apply to those family members who were included in a principal investor’s petition to remove conditions. The rule improves the adjudication process for removing conditions by providing flexibility in interview locations and to adopt the current USCIS process for issuing Green Cards. Finally, the rule also offers greater flexibility to immigrant investors who have a previously approved EB-5 immigrant petition.