I don't believe Meteora could be considered more experimental than OML. It totally is a deliberate attempt to sound like Hybrid Theory and even the band has admitted it many times. There are even songs on Meteora that are direct analogues to songs on HT. OML, on the other hand, might not be something mind-blowing in today's pop music landscape, but it is very different for the band itself. I don't find anything interesting about the two Meteora songs you've mentioned - HTF is as generic as an early Linkin Park track can get and it's kind of ridiculous how the band hyped it so much for starting on the off-beat. NL might have an interesting instrument, but it still follows the most standard structure, the Japanese flute plays the same melody a gazillion times and it doesn't really seem more different than using, say, key chains, car alarms or party sounds. Everybody has different opinions on what experimentation is, of course, but the only track on Meteora I actually believe to explore different territories for the band at that time is Breaking The Habit. Everything else is a copy of HT. One More Light might not be something no one has ever heard before, but at least it's something entirely new for the band. It might not turn out to be Linkin Park's best record so far, but it will most certainly feature more experimentation for them than albums like Meteora and LT and it will obviously be the band's riskiest record to date.