Of course it was a publicity stunt for the Chicoms.
Moscow used to have ONE protestant church, kept open for the same reasons.
But going there sends a message to the CHINESE Christians, that the president is on their side; and forces the Chinese government to have to state that religious belief is officially permitted--a tool which Chinese believers can
use to try to expand their own freedom.
It's only a tiny opening of a door, but it's a start; and more than the State Dept. would have wanted (they would probably prefer to avoid the topic altogether, for fear of embarrassing their hosts).
I agree with you.