My google-fu has been pretty weak this morning. That or the very few articles, including wikis, that I'm finding have very little to say on the matter. I'm basically looking for a summary (cannon) of what has happened in the 100 years since the BG novels and what took place within Descent Into Avernus.
Try to search for "Spellplague" (the switch from 3.x to 4e) and "Second Sundering" (the switch from 4e to 5e), I'm fairly certain one of the Forgotten Realms wikis has at least a basic recounting of the important events.
