I don't think a TA2K will go there, looking at the layout, it would be a great location for a Hyper/Giga-Coaster station going out of the park to the aquired area behind the park. Back when this land was purchased I recall a news announcement that Knott's wanted to expand this area. Well, immediately after the economy took a big fat dump in SoCal, with the resulting reduction in visitors, the only financial option they had was to build a parking lot.
A "Challenge Park" at Knott's would be a failure. There are some nice Malibu Grand Prix courses in LA that would render this addition a waste. Look for park expansion in this area with an inverted coaster, stand -up and a Giga/Hyper along with a few twist a pukes. Don't think that Cedar Point would give up a record to another of their parks, after all, they did with Supreme Scream (240' to 250')!
For a long time (till early 80's), Knotts led southern cal in coasters with the CorkSkrew and Montezuma's. When I was young, Magic Mountain was a joke with only the Revolution and Colossus. The rest of the rides rotated (Bobsled, Shockwave (killing 3 after the track broke through at the bottom of the first loop). Ninja was the first major permanent install (a flop)followed by Viper, Batman, Superman, Riddler, and now Goliath). History has a knack of repeating itself! I think in this case, Knott's may not have the most, but they will likely have the most cutting edge!
Knott's has a history of making wise choices with regard to ride installations, with only one failure "windjammer". This was only put in because of low cost and high expectations. Look at the Log Flume and Calico Mine. Two great "theme rides" that may never be matched. That's a damn good track record. Even windjammer was a good idea, but I think they should have left the Soap Box Berby, it was more fun.