i believe that these countries, that is, China and Russia, are only prudent and await the conclusion of any legal battles that Trump is putting in place I think that once there will be no more legal aftermath they will obviously congratulates with Biden
Exactly. It's not just China and Russia. That didn't yet congratulate Biden but why does it matter for US president if the two don't congratulate Biden?
Biden's position wouldn't be demoted if the two don't congratulate him. They'd be waiting as well what Biden could bring to them. If Biden is going hostile to China like Trump, Xi Jin will just ignore him unless Biden himself will call.