Yes, the OE plugs are Platinum. Never even heard of Ruthenium!?
I used NGK Iridium when I replaced mine. Iridium are supposed to last about 20k miles longer than Platinum and have a higher heat range, so the Ruthenium plugs will be extended in heat and mileage range from Iridium.
I don't see any issues in fitting them, just depends on the price of them.