When in creative you can fly through a nether portal with an elytra and it will transport you to the same x,z coordinates in the nether as you were in the overworld, similar to the previous eating in a nether portal bug (MCPE-54519). It can also create an invisible portal in the nether as shown in the video. I first found this on a realm and came back and tested it in a new world on my phone and it happened both times. I managed to get to the far lands using this bug quite easily.