Darkman is weird. It's Universal Monsters kinda but also not. The nature of a lot of those films means that the inclusiveness isn't always specified. It's mainly included due to the specifics of the wider franchise rather than the actual film itself. Statements suggest it's Sam Raimi's own Universal Monster, but was that continuity intentioned? Well, probably not, but the theme park seems to suggest a continuity with all Universal Monsters material, so it's taken in.
The Jason X connection is more notable. I think I'd only add things that directly connect rather than everything if I did that... which would pretty much be every Dracula/Mummy/Frankenstein/Wolfman/Gillman film, the 1999 Mummy/Scorpion King series, The Mummy (2017), and Renfield. I'm not planning on that, but, well, yeah? I guess it's a pretty solid connection. (Insert non-existent crying emoji)