Gripen has US engine, still it is exported... Even to nations that were almost forced to accept cheap F16's.
I do not see any real issues with Russian engine in a JF17. If I remember some folks back decade a go telling me that it was a paper plane I was pretty sure they were wrong. Now I flew the JF17 simulator, sat in an operational JF17 and talked to most of the test pilots, crews and engineers. I think I can say that it is not a big issue. I am not going to tell you more cause I not like to hurt or degrade anyone or any nation. Leave the drama about what will or will not without the facts.
Sweden (SAAB) has an agreement with the US to re-export the engine in their planes to other countries, the US can still veto sales of the Gripen to "unfriendly regimes"
China (CAC) has an agreement with Russia to allow re-export of the engines to Pakistan and six other countries.
reference here
Pakistan has no agreement with Russia in fact to quote "But the sanction doesn’t mean adding Pakistan to the list of states of direct military and technical cooperation with Russia."
Therefore with reference Blackstone's original query
An interesting scenario is who will sell JF-17/FC-1 to new buyers?
Only CAC will be selling them to new buyers who want JF-17s with engines.
Do you see a real issue now?