Gargoyles season 3 aka Gargoyles: The Goliath Chronicles is said to be non-canon by the fans all over the internet but do we have any statement saying the same? Like any words from production member or any official from previous or current season members?
It seems to NOT be considered canon even according to series creator, Greg Weisman who states, that he ignored the third season's plots, when he continued working on a canon Gargoyle comic series sometime later.
As the following passages explain, much of the Goliath Chronicles team had been fired and replaced by new writers shortly after the pilot episode and didn't seem to understand the the story/characters prior to this season.
The Goliath Chronicles was the name of Gargoyles' third season. Whereas the first two seasons had aired in the afternoon in syndication, as part of "The Disney Afternoon", Chronicles aired on Saturday mornings on the American Broadcasting Company (ABC, which had recently been acquired by The Walt Disney Company). The series originally aired between 7 September 1996 and 15 February 1997. The series was known as The Goliath Chronicles because Goliath would give a short monologue at the beginning and end of each episode.
After the first episode, "The Journey," all the producers and story editors (including series creator Greg Weisman), along with most of the other crew, were replaced. The following twelve episodes were poorly received by most of the fans, for various reasons including poor characterization and continuity. As a result, it is not considered to be canon, and was ignored when Greg Weisman later continued the Gargoyles storyline through Slave Labor Graphics' comic book series.
According to Weisman, the original crew "had considerable freedom the first two years" because Gargoyles was a syndicated series, while Chronicles "was network and had much tougher standard and practices rules." Weisman also stated that, "Part of the problem was that the staff of Chronicles took springboards I came up with and then went WAY south with them." For example, the episode "And Justice For All" was based on Weisman's plan for Goliath to be on trial for his sentience, but in the actual episode he was on trial for robbing a jewelry store. "Ransom" was intended to have tricksters Anansi, Coyote, Puck, and Raven, with Raven kidnapping Alex; the final episode had Alex getting kidnapped by a corrupt New York City politician. The episode "Runaways" originally had Brooklyn being whisked away be the Phoenix Gate only to be returned to his correct time 40 second later and 40 years older (the story as intended was eventually produced with Gargoyles SLG issues "The Gate," "Tyrants," and "Phoenix"). Much of this may be due to the fact that the team working on Chronicles had very little time to familiarize themselves with the original show before they began production, badly hindering their efforts.