Only our foes get this kind of the benefit of the doubt:
The Wall Street Journal reports that the “imminent end to China’s island-building work could signal a willingness to seek compromise with Washington and rival claimants in the South China Sea.” China's President Xi Jinping is scheduled to visit the US in September.
Are they joking over at the Wall Street Journal?
How is completing a project that violates international law and stokes tension a sign of seeking compromise?
This is just the familiar ratchet of aggression: take land; negotiate to keep new land; wait for the furor to die down; then start the process again.
Lather, rinse, repeat.
So, no, this is not a sign of compromise by Peking. It is a sign that China wishes to consolidate their illegal gains with a pointless international agreement.
Or just talks about such an agreement. As long as they have the islands, China doesn't really care about the details of how they consolidate their gains.