In a way yes, but as long as you are able to earn enough points before the end of the season to buy all your gear, you will still have time to push rating.
The only advantage to playing 5s is you get access to your gear to make a rating push earlier. But skill still bars them from titles/mounts which ARE the reward for PvP. If you are just in it for the gear you will get it regardless of what bracket you play.
That said, we don’t know how long the season will be. So if they aren’t giving the season enough time for 2s players to buy all their gear AND have time to make a serious push on the ladder… well then they really goofed it.