I agree that new content is better, however, it is much quicker for them to simply scale EC up to 55 then to make an entire new operation. For a lot of people, it will be new content anyways since no one runs it anymore. I would also be ok with scaling it up to 55 and making it a solo operation with three companions, but that would take a lot more work probably.
I don't care how simple it might be, and I have extreme doubt that it's as simple as you think. It is a complete waste of time and energy for them to spend an iota of effort on this.