per Multiversity (as of 2016), it's a connected universe when it was Trinity and TT books only
Not sure why anyone would think the GL book would take place before Superman; if there were Lanterns around on Earth, where were they when an invasion force was attacking the planet? Or when an alien shipped clearly landed?
The OGNs have all sold well; Earth One isn't at all redundant; DC is interested in more of them, in fact, some of prestige format books doing well, particularly when they are collected, has made DC more interest in OGNs, but DC just hasn't spent the time editorially doing anything with it.
For example, even though the Superman E1 books all did well and supposedly JMS stated he only had ideas for three books, no one else has been assigned to do anything with the plot threads JMS left hanging NOR done anything new. Instead, DC did American Alien and The Coming of the Supermen, both of which sold well as collected editions, but hasn't done anything with Superman at all otherwise.
Likewise, having Cereal Lord do the Bat book made that a cluster fuck where he's gotten two books out in the entire time where it's clear he has no idea what he's really doing. Morrison being slow is Morrison, and TT has more to do with the book not selling well than with Lemire having any issues with deadlines, etc.
Didio, et al. may not be interested in a Ultimate universe any longer, but they are definitely interested in more OGNs; the whole point of the Zoom line makes that clear.