What replaces them?
The game no longer has a backbone of content for leveling purposes. It's just a mishmash of many separate systems with no unifying direction.
On top of this, the value of leves has been vastly reduced now that they are designed solely for soloers. When the system could be expanded tenfold from what we have now, it's no longer important to the game as a whole and the developers can merely choose to ignore the system, rather than make it something fun that fits the multi-class system they have here.
What are we supposed to do, go back to Stone Age and kill monsters in the field for hours for no apparent reason? That has no mass appeal. Are we going to complete sidequests instead? Crappy sidequests, mind you, since there has to me tons of them to make up for the fact they're one-time wonders.
Basically Yoshi-P stated that Guildleves have been deemphasized, but did not go on to explain what he intends to replace the system with. What is his grand plan?