Alright, so preliminary prediction time. After refreshing my memory on Horizon Holidays, I came to the conclusion that, while Holidays Mixup certainly could well be the first Playlist remix, it won't be a 1:1 redux--the Sian Roadster, its Secret Santa car, is now in the Autoshow, on top of Secret Santa, of course, seemingly no longer in the picture for Holiday Updates in general now that we're in End-of-Life. 'So how are they going to handle this?', we must first ask ourselves.
Well, I simply looked back at the Holiday Update before that, Year 1's Holiday Special. Its Secret Santa car happened to be (ugh) the Peel P50, which hasn't appeared as even a Hard-to-Find since Horizon Anniversary, and, most importantly, was never added to the Autoshow. If they want to give post-Series 13 players a chance to complete their collection of the crappy little red devils, then this update would be the perfect opportunity to bring it back as a Hard-to-Find--most likely as a Series Reward. Whether that's for 160 points or 80 points remains to be seen, but I do think this car will absolutely return next month. The other two Secret Santa reward cars that haven't been added to the Autoshow or made Hard-to-Finds also stand a good chance of either appearing as Hard-to-Find rewards for Seasonal Championships or Series Reward Hard-to-Finds, but I won't factor them in yet.
The Playlist itself... there's no sugarcoating it, this will be a grab-bag update with no real theme linking them. There's two possibilities in my head, considering new cars have been teased; one is that this update will consist entirely of New-to-Horizon and returning cars, with one New-to-Forza car around Christmastime if we're lucky, and the other involves a mix of New-to-Horizon, returning and New-to-Forza cars, like we've been getting over the last three months. I'm going to assume the first for now, and revisit the second at a later date--it seems like our most likely bet considering the circumstances. For this prediction, I'll be running with the very loose theme of 'better late than never', basically cars that are supremely late to the party and would be seen as welcome additions.
The Holiday Grab Bag ('Better Late Than Never' Edition)
Series Rewards: 1962 Peel P50 (80 points), 2019 Aston-Martin Valkyrie (160 points)
Summer: 1993 Porsche 928 GTS (The FOMO 928 appeared late in FH4, it should only stand to reason it would appear late in FH5 at this point. I would assume this to be the headline car, if only because 'better late than never.')
Autumn: 1995 Ford SVT Cobra R (I know, this is an SN95 simp talking, and yes, this is another Mustang, but again, the whole loose theme I've been running with is 'better late than never'. This is a car I'd love to see make the jump to FH5, even though we have the Terminator Mustang around to basically supplant it.)
Winter: 2022 Lamborghini Huracan Sterrato (This being Christmas week, we're almost certain to get a Secret Santa reward car equivalent around this time. There were four contenders in my head for this--one was the Sterrato, of course, the other was the Koenigsegg Gemera, with dark horse contenders swooping in in the form of the Maserati MC20 and Lamborghini Revuelto. What ultimately pushed the Sterrato over the line for me was the addition of the 911 Dakar; if we're getting one off-road modification of a VAG legend, then why not the one everyone's been asking for, its stablemate? Also, expect the Gordon Murray T.50 to reappear here somewhere.)
Spring: 1998 Aston-Martin V8 Vantage V600 (Making the jump from FM2023 to Horizon at the potential end of the road. This feels like exactly the kind of 'highly requested New-to-Horizon car' that would appear at the end of potentially the second-to-last Series with new cars, and it'd be a neat one. I certainly wouldn't be opposed to it!)
As for FH5's future beyond this Series... it's certainly clouded to me, but here's what I think. If FM2023 gets in on the 911 60th anniversary celebration as well, then it'll signal that from the Holiday Update on, Forza will basically act as a united brand. If something happens in FH5, it will be safe to assume FM2023 will either do similar, and vice versa. They might've tried this already with the Jordan Camaro in Hidden Horizons, since that was a Forza-wide collab. In other words, it's possible FH5 will be on a light form of life support, getting some carryovers from FM2023 here and there while coasting on Hard-to-Finds. If not, then we're back to square one.