Alright. I know I don't shut up about my predictions, but I have to do this. I want to make the reasons why I support these predictions.
DISCLAIMER: Please do not think I am expecting to be correct. I will most likely not be correct, as Smash has been proven to be nothing but surprises. I will say that SharkLord brought up a good point about how we have constantly hyped up characters as super likely, and they never get in. I agree. However, I just want to throw in my two cents based off the merits of the following three:
CP9: Monster Hunter, March
This one I am the most confident in by far. First off, we still have the Monster Hunter Mii costumes left from Smash 4. Second of all, the next batch of Smash amiibos come out on the same exact day as Monster Hunter: Rise does. The release dates of amiibos tend to pinpoint the next character, as it has done this repeatedly in the past. Nintendo is also pushing Monster Hunter quite heavily, almost in a similar fashion to Dragon Quest XI S. Monster Hunter even got its own direct for crying out loud. Monster Hunter is also Capcom's most popular series, and is one of the most popular series in Japan. Sephiroth destroyed the fan rule of no second representatives from third party series as DLC, and Monster Hunter is represented in Smash. So, Monster Hunter definitely has a lot of things going for them.
CP10: Ryu Hayabusa, E3 2021
Ryu Hayabusa has circulated around Ultimate speculation, a lot. However, something interesting has happened. Vergeben, a leaker who has gotten nearly everything correct, has claimed that Koei Tecmo is in talks with Nintendo. Ryu Hayabusa is a pretty iconic retro character, and Koei Tecmo's most iconic character. Considering that Koei Tecmo has helped immensely with Three Houses, and Breath of the Wild: Age of Calamity, it is safe to say that Nintendo and Koei Tecmo are quite close.
CP11: Rex, September-October
I expect a first party to end FP2, as this pattern has happened in Smash 4 with Corrin (Bayonetta was with them to be fair), FP1 with Byleth, and now we are currently in FP2. I do not think we are only going to get one first party, and we could very well get a second one. Now, I feel like Rex has some things going for him. Xenoblade Chronicles 2 was very succesful, and is quite popular in Japan. In fact, according to Shroob, Rex is the most wanted character in Japan. Please feel free to correct me. Sakurai has also played Xenoblade Chronicles 2 before. Now one roadblock is the Rex Mii costume. However, this came before FP1, and Sakurai couldn't get Rex in the base roster due to time constraints. This shows that Rex was actually considered for the base roster, but Sakurai didn't have time. Hero and Steve were also considered for base roster, but they became DLC later on. I feel like if Smash wanted to represent a new first party game, then Xenoblade Chronicles 2 is one of the largest that is left. Similar to the case of Monster Hunter, Sephiroth broke the "No second third party representatives for DLC" rule. While Rex isn't a third party, this does show that any series in Smash can get a second representative. Plus, Byleth got in as a DLC character, and they are a Fire Emblem character, well represented in Smash.
Okay, there are my few cents on the last three DLC characters. I hope you enjoyed! Feedback is heavily appreciated.