What sets Xiongan apart from existing Chinese tech centers is its real estate policy. Forms of public housing are going to play the dominant role there. I don't think they've released any detailed plan yet but the goal is to make housing available for everyone working there.That’s not true. In the U.S. Austin and Seattle are also major tech centers. However I agree that it is best for tech centers to form organically instead of through governmental intervention. If the soil is there, the efforts will bear fruit naturally.
The biggest economic injustice in China in the last 20 years was the real estate model. Investments from the government and businesses and the workers' hard work improved land value tremendously, but the value went to the pocket of the existing real estate owners. If you bought an apartment in Shenzhen 15 years ago your investments would have a 20 fold return even though you made no contribution to the city. Some young people working in Shenzhen is going to spend 20 years of his/her time working for you. This could be partially solved with a capital gains tax but the vested interest has proven too powerful so far.
Xiongan is a greenfield experiment on a new model of urban development. If successful this could lead a drop of real estate prices in Beijing as companies and work oppotunities move to Xiongan with its cheaper real estate costs.
I remember there are huge swamps of undeveloped land in Pudong, Shanghai as well.