The short answer is, yes.
While it is true that the more gas you pay, the sooner your transaction ends up in a block, additional gas does not actually guarantee a faster transaction. For example, times of high congestion can cause your "high gas" transaction to be pushed back due to others with even higher gas.
A block takes as long as it takes to create. Adding more gas doesn't actually speed up the block time, just your position in the queue to be added to it.