I think the question to ask before that is who requested the phone conversation in the first place... that would then give us some hypothesis to work on what topics were on the discussion agenda
Well at least he didn't ask to speak to the 'highest guy' in the US military
Blinken: bail us out.
Yang: no.
If you read the news, the phone call was at the US' invitation
after the Alaska fiasco, blinken hated yang so much, he resorted to personal attack. he claimed "yang has no real power, he is one hundred miles away from China's inner power circle". then why bother to call?
He wanted to make up for his bad behavior and wants some Chinese cookie to go with Chinese tea.
So this was the exchange that took place.

China's Yang Jiechi told U.S. Secretary of State Blinken today that the U.S. should improve its "grave human rights abuses" within its borders, instead of diverting Americans attention by lecturing China.
Maybe Yang was referring to:
-The 100 killed in gun violence each day
-The 3 killed by police brutality each day
-The bottom 50% Americans who hold only 2% of all U.S. wealth (while the top 1% holds 30%)
-What else do you think?