It's just time gating to keep you at least 2 months subbed, nothing more and nothing less. It's the same for the quest quest line, that is chopped into 8-9 parts, so that they can drip feed it to you weekly. I very much doubt this will ever change, since it's very deliberate. The incentive to go normal has pretty much been debunked since Ghostcrawler - by himself - as you already noted.
You are welcome, Metzen. I hope you won't fuck up my underground expansion idea.