Won't really effect flavor, once the boil is over the hops have done their job.
You do need to oxygenate the wort but if your carboy is glass I would not recommend shaking it. It's heavy and if you slip you could end up with a mess and lots of broken glass. There are plenty of stories on this forum about trips to the ER caused by glass carboys. A vigorous pour will do the trick, or if you're siphonong into the carboy you could just stir the pot once it's cooled, before the transfer.
If you've already pitched your yeast don't oxygenate now. It's will be fine.