Remember. Take these theories with a grain of salt 🧂 yet we still want to believe.
Here are some of my theories for Deadpool & Wolverine:
Ophelia Sarkissian / Viper and Bob will appear in the film as "surprise cameos" albeit with their alias, "Madame Hydra" and "Agent of Hydra." (Since in their original appearances, The Wolverine and Deadpool, they couldn't be referred to those alias due to Marvel Studios holding the rights to Hydra at those times, but since Deadpool & Wolverine is produced by Marvel Studios, the two of them will be referred to their comic alias.
Out of respect for Hugh Jackman (or possibly Ryan Reynolds), Deadpool & Wolverine will not have a post-credits scene. (I hope 🙏 this does not come true)
Similar to Men in Black: International, there will be a painting in the TVA showing both Loki and Sylvie meeting He Who Remains for the first time as a reference or representation of Loki.
Salutes of Loki, Mobius, Sylvie and He Who Remains will appear throughout the TVA.
There could also be a painting of Mobius
There's a possibility of The Watcher making an appearance in Deadpool & Wolverine.
In a similar matter to Loki himself in the Time Theater in Loki, Paradox will show the memories and future events from other variants of Wolverine in the Time Theater to both Wade and Logan as he plays Logan's life in the theater from X-Men to Logan and will also play a clip of Deadpool and Wolverine meeting for the first time in X-Men Origins: Wolverine, when Wade was Weapon X.
Similar to Nichols Cage's cameo as his version of Superman in The Flash, Channing Tatum will finally play his version of Gambit in the film as one of the many "surprise 🫢 cameos" in the film. (Hey it's a possibility)
Archive footage of various characters from several of Fox's Marvel films (not just X-Men, but Fantastic Four and Daredevil as well) will be used in the film to represent those characters.
Deadpool will use a Sling Ring
Paradox will also mention and reference the events of Loki Season 1 and Season 2.
That's pretty much it. Can't wait for Deadpool & Wolverine to come out this July.