The book will (sadly) be a standalone
Despite its popularity and huge potential for lore that has enough meat for an entire trilogy (much like Bloodbound), Immortal Desires has one aspect to it that may prevent it from getting a sequel: it has multiple love interests. Since the new VIP scheme started, all books with confirmed sequels have only one love interest (Surrender, Crimes of Passion, Untameable, and The Cursed Heart), while books with multiple love interests (Wake The Dead) are standalones, despite having more story to tell and being rushed to fit into one book.- Counter-point: Shipwrecked, the first book released under the new VIP early access scheme, has only one love interest and is a standalone, so is The Princess Swap, which is a special case, a dual lead book where each MC has only one LI.
- Counter-counterpoint: The notion of VIP books having sequels wasn't established until Surrender. At the time Shipwrecked was ongoing, all VIP books were always standalones.
- Confirmed as of August 24, 2022; the book is a standalone after all.
- Update: As of December 19, 2022, this decision has been reversed, and there will be a sequel coming in February 2024.
Gabe and/or Cas (but most likely both of them) are canonically bisexual
Since, in addition to the fact that both of them don't seem to care about Parker's gender, they tend to bicker a lot between themselves in a way that suggests Belligerent Sexual Tension (irrespective of their own genders), as well as the fact that most vampires in fiction (and not just Choices stories) tend to be bisexual. With several sneak peeks of Book 2 pushing the "throuple option", it's likely that, if Parker chooses to date Gabe and Cas, they will date each other as well, having bonded over their mutual feelings for Parker. Lewyn and Astoria will either die or forced to step down by the end of Book 2
With Book 2 introducing a new threat armed with weapons meant to combat Vampires, it is possible that Lewyn and Astoria could die, no matter how powerful they are. Alternatively, their covens could see them as incompetent by the end of Book 2, having failed to stop a threat against them twice, and it will be decided that they are unfit to lead. Parker will have to choose between Gabe and Cas by the end
Despite Parker clearly having feelings for both of them, the numerous "double heart" choices, and the implication of a threesome mentioned in the Choices Insiders, it's possible that Parker will still have to make a choice between them. As well as Unbridled forcing the main character to choose between the two love interests at the end (in spite of being able to get romance points with them both right up until the finale and the potential threesome), Book 2 seems to be pushing away Cas in favor of Gabe, it's repeatedly stated that Parker is going to have to choose eventually, and the aforementioned Unbridled scenario could well happen in this book as well. The traitor described in the description for Book 2, Chapter 11 will be none other than Parker's own mother
It's possible that Parker's mom A) somehow discovered the existence of vampires between Book 1 and Book 2, or B) the memory-erasing spell failed to work properly on her (just like it failed on Libby). Either way, she now knows that vampires exist and that her only child has become one of them. Wanting to get them back at all costs, she would have joined the Forest Bureau to eradicate the vampires, hoping that she can turn her child back into a human.