Yeah, let's go into the place that we've been TRYING to go into for a while now.

Y'know, just casually walk in, wave hi to Alpha Squad.

The problem is not necessary the idea of the Core having something in it, the problem is what is inside it. No one has been able/willing to address that in detail yet. "It has stuff. Hurr."

As seen above, Three Rings makes ancient promises which have yet to be accomplished nor announced in time frames. They could at least tell us what is in progress rather than throwing "we will do it eventually" as they constantly have.

Player theories for what comes after T3 include but are not limited to: T4+, Shadow Lairs, some giant boss fight, a planet within the planet, itching, and discoloration of fingernails. If symptoms occur exceeding the duration of three days seek medical support and be sure to inform them your problems were caused by a placebo medication which was not created by medical professionals, rather a group of untrained chimps wearing pants as hats while flinging fecal matter within the confines of their facility.

My previous response was due to mental friction against the context of the original post which essentially reads as "I want new stuff so make it for me". I retain that perspective because no detail is given by the original poster.