That is a factor.
Chinese import of Russian oil is about 2.1 million bpd. 1.4 mbpd is by sea, the vast majority of which is imported by independent refinery arrays. The Govt refineries are not the primary importers.
So about 700K bpd is arriving in China by pipeline. It looks like 800-900K bpd are independent refiners not very far inland but not owned by PetroChina (the big govt refiner).
China doesn’t really have anywhere else it can get 2.1 mbpd. No one else has that sort of free capacity for export — having pre-existing customers. This has been reality for quite some time.
One does wonder at China’s response to their refiners getting sanctioned. There were suggestions they might do a deal for their rare earth export controls, but this event is unlikely to encourage that.
A case can be made for Russia, China and India having isolated the US and EU from the world community, and it will be noted as being due to their behavior.
Few pipelines operate at maximum (nameplate) capacity and an increase in capacity operation might handle the extra volume.
This effort could be greatly limited or mitigated in effect.