Follow TV Tropes
Some issues with the Retcon entry:
On the first point, IDK if there's been an official explanation, but Leland Chee fixed a similar Continuity Snarl with the Young Jedi Knights series by retconning the series' first third's Imperial Big Bad as a Renegade Splinter Faction. So there is a precedent for what you're saying.
Regarding the second point, Isard's Revenge has the Lusankya in the final stages of being repaired after its capture in The Bacta War, and the New Republic brass states that depending on how long it takes it could be available to help fight Prince-Admiral Krennel (it wasn't). They apparently used it as a mobile biowarfare lab for a while, then put it into an active military role. The Essential Chronology has Lusankya being used in combat in the Orinda Campaign about three years before BFC, including multiple inconclusive duels with the Imperial SSD Reaper under Pellaeon. It also turns up in the Enemy Lines duology (can't ever forget Operation Emperor's Hammer), where it is eventually destroyed in a ramming attack against a Yuuzhan Vong worldship. So yes, this was definitely retconned. Possibly the Lusankya was undergoing repairs at the time of BFC (we know from other sources such as I, Jedi that Imperial II-class destroyers are very maintenance-intensive and SSDs may be similar) and was simply unavailable.
EDIT: Corrected a mistake.
Community Showcase More
How well does it match the trope?