Perhaps not. But the flag allows for direct I/O for data, bypassing buffers which can be overrun with certain size blocks, potentially causing dirty buffer depending on the machine being used. My understanding is that it’s “more reliable” for writing (especially on shitty USB Flash drives) and getting the exact ISO properly written.

But it could be useless all the same - I’m just pointing out that OPs command is not the one recommended by Fedora when writing their ISO. Also OP is less likely to pull the drive before buffers have flushed this way.