On 6.0.5 Neoforge, Enderwards prevent player teleportation via Ender Pearls and the Teleport spell payload, but does not prevent teleportation by Endermen themselves.

This is evident as I have a base built in the End with a nearby Enderman Farm, and thus a... real abundance of Endermen. Use of Sunlamps prevents them from spawning, but they can teleport right next to the Enderwards, in an area where I definitely cannot and get the "an unseen force blocks your teleportation" message.