For the last 2 major faction events, the controversial retcons didn't come from the region itself but from the random champs they decided to retcon into the area to fill it out.
That is an important point.Looking at
for Freljord &
&
for Shurima as the biggest examples of this point.
It'd probably be worse that Mt. Targon is such a sparse region, means to make it an exciting event they'll need to retcon more champs into the area.
Well,Riot would ideally hold off on doing a Targon event until there are some champs with Targon invovlement.
There is also the tactic Riot can take where they use non-champion characters to supplement the cast during the Targon event.Afterall,the lore doesn't have to only feature or be about the champs.That would make the world very uninteresting.I'm talking about important NPCs with an involvment in the story or have a relationship(s) with a champ(s).
This way,Riot doesn't have to randomly retcon unrelated champs just to add to the cast of said event.