I think Drew sort of assumed his work would become the core of Elite? The books are pretty cool from what I understand, but it's worth remembering who actually owns 'the property' of elite. Frontier. So whilst I completely respect the work he's done, expecting a business to just hand over creative control of lore to someone else, is probably a bit of a stretch in expectation.
It's less the case of 'lore' changing; so much as who is ultimately driving that. Which should never ever be in doubt. Frontier. Lore exists to describe and serve the game world; not so much be the concrete shoes it's forced to wear. As for creative direction; that has nothing to do with Drew, and never did. He's a cool author who wrote a bunch of stuff based on the universe David (Braben) and Ian (Bell) created back in the day and it's cool that a lot of that was able to be tied into the game.
We have no idea what deal, if any, existed for that crossover material, but I don't think we can just assume Drew had some sort of monopoly or directive aspect here. And since Frontier seem to have decided Elite doesn't need a creative director or producer (the credits refer to people no-longer associated iirc) folks can't expect miracles.
I'm not being overly presumptuous here. The people who own the IP will likely desire to have creative control, and that's a fairly normal arrangement. That they don't appear to have much creative direction, or tying much of anything to lore, might be because Sandy can only do so much. Frontier should probably have invested more interest and personnel in that space, and it's a shame they haven't.
They haven't, which doesn't surprise me really, because David was always more interested in the universe and bgs and how all the mechanics work and I can't remember him really waxing lyrical about lore. Stuff tends to start at the top? Just say'n.