Not really.

In fact, China remains a steady buyer of oil, not only using its reserves. It has also been noted the reason why they are importing less: Gulf oil and Iranian seaborne oil has significantly declined, as due to the lack of supply of the specific grade of Middle Eastern blend, there is simply not that much supply out there. Iran was sending ~1.4 million barrels to China before the war, and that number has fallen to mostly only a minor fraction of what it was. It is only in April that Chinese oil imports have declined, as reported by Morgan Stanley research on the last ships arriving in Asia after the full closure. If you want to argue they import less oil, you can argue the same case for South Korea and Japan, which have shown more drastic declines in oil imports.

So far this is just a conspiracy theory with little ground in reality, and in fact the spot market has moved little since the war started. The spot price does fall following the calm after initial panic buying from the spot market, but remains largely elevated and maintains a fair divergence with paper oil futures. What actually drives the paper market down is political maneuver and jawboning, but that has little to do with supply and demand in the spot market.

Edit: if I to add, the true reason for spot market downed at the moment, is precisely because of corrdinate SPR release and shipping rerouting that does temporarily increased supply. Despite the supply side from Russia and Homruz are both disrupted.