Anderson wasn't involved in Dark Empire.
Yes, I believe his only involvement was having to re-work "Jedi Search" to account for a torn-up Coruscant coming out of the events of Dark Empire. The World Devastators are mentioned too.
I stand corrected. Though I could have sworn he had some kind of involvement due to the use of the holocron, the mention of Baas, plus his descendent being the gatekeeper as well as the link between Vima and Nomi Sunrider.
There seems to have been some kind of interplay going on there at Dark Horse.
Regardless, in hindsight 'Dark Empire' is a bit of an oddity. Tone and art style aside, it sticks out like a sore thumb wedged between the Thrawn & Academy trilogies. Plus, aside from the odd line here and there nothing in that story seemed to matter. If nothing else, Luke's fall to the darkside was trivialised somewhat by his near instant redemption thanks to Leia and her glowing foetus magic...