Are you able to elaborate more on this?
My understanding was that Thorpe Park was on something of spending spree from 2000 to 2012 due to all of the new rollercoasters and flat rides that were built after Tussauds bought the park, but was there a lull around 2006 ?
I'd definitely agree with AT86 that the park did slow down around 2004 onwards with investing.
The early 2000s after Tidal Wave was partly as a result of the Thorpe Park fire that happened in 2000 that resulted in the destruction of Wicked Witches Haunt.
Zodiac came in originally as a Retrosquad like addition to add additional capacity due to the loss of two rides that season.
Vortex, Detonator, Colossus, Nemesis Inferno, Quantum and Eclipse were likely to have been planned as a result of the fire and from the insurance money that came with it.
It slowed down from 2004 onwards. Samurai came from Chessington which was that season's addition.
2005 did result in Slammer and Rush which was a double deal with S&S. Rush replaced Eclipse which moved to Chessington as Peeking Heights. There was an urban legend from that a ride host mentioned a long time ago that they got Rush for free and are not allowed to remove Slammer without Rush (not sure if that's true or expired). Flying Fish went on hiatus for two seasons.
2006 was Stealth which I'd definitely wouldn't be surprised if it was based on Xcelerator.
2007 is Flying Fish's return which ended up in a different part of the park. It was originally located where part of Stealth and the Dodgems are now before 2005.
2008 was a new film in the 4D Cinema and 2009 was Saw the Ride. 2010 followed with Saw Alive.
In 2011, Thorpe Park acquired Storm Surge which operated at Cypress Gardens in Florida (now Legoland Florida).
2012 was the opening of the Swarm.
Forgot to add that the original Zodiac was replaced like for like by a newer enterprise which was Cyclone at Drayton Manor around 2005/6 as well.
From 2004 onwards, the park has definitely slowed down significantly with it's investments with multiple relocations of secondhand rides from both within Thorpe Park and other Merlin parks taking up the bulk of it's new ride investments other than Slammer/Rush and the coasters.
Any investments before then would've been as a result of the fire in 2000 either partly or entirely.