I am looking to camp this week at Poplar Point, Loop E. I know this is normally first come first serve, but I also know that last year reservations were required and not all camp sites were available. Is it first come first serve currently?

Loop E is always first come as far as I know. I've also been twice in the last two months and E was almost full both times. You might be better off doing a reservation.

Wife made reservations

If you are going mid week, you stand a better chance of getting a site. Weekends, not much chance...

Yes a reservation is always best.