Actually you would have more power with this arrangement, assuming it is all wired correctly than you would with a 30 to 50 dog bone. A single 30 amp circuit has only one hot, this would give you two hots, for a total of 60 amps of power or 7200 watts, twice what the single 30 amp would give you. This is why it is imperative the two 30 amp circuits be on apposing legs. If they were on the same leg, you would potentially have up to 60 amps on the neutral, something that is cancelled out when you use two phased legs.
When using a typical 50 to 30 amp dog bone, the two hot legs are fed by a single 30 amp hot leg, so a single neutral is not an issue. You get power to both sides of your breaker box, but total only 3600 watts.
Bottom line, yes, this will work, if the pedestal is wired correctly, which we have to assume it is. Other than cost to run a 50 amp line vs the second 30 amp line I can see no reason to have two 30 amp plugs on one pedestal, unless it is designed to be shared by two sights...something I have not seen either, even in very old campgrounds.
Enjoy camping, spring starts TOMORROW !
2011 Toyota Tundra double cab