Jergal is, by far, the most interesting of the Forgotten Realms gods - someone who found being all-powerful boring, so instead of engaging into war, or conquest, or madness, he just... stepped down. And turned his successors into a personal reality TV. Maybe he isn't too pleased that the Dead Three returned (especially Myrkul) and is planning something behind the scenes?
EDIT: To those of you who don't know - Myrkul is the main reason why mortals are so afraid of death. In Jergal's tenure, death was mysterious and unknown, but Myrkul turned it into something inspiring terror and dread. On the other hand, the (initially) good god of death, Kelemvor, started spreading around the word that those fighting evil will automatically achieve Paradise, turning every good adventurer, paladin etc. into fucking ISIS, storming evil temples, making suicidal charges etc. Until Ao told him to stop this shit, since the evil deities were complaining to him.