Are you talking about chain rings 46-30 (front) or cogs 24-26 (rear)?
No triples have not going out of style particularly with "randonneurs" multi days riding with paniers and camping gears.
I was thinking 46-30 up front. Shimano and SRAM would both like to move away from triples to save money. The need for them is going downhill as others have pointed out because you can run a huge cassette in the rear and you're not missing all the in-between gears with 10 or 11 which you were when running 6 or 7.
Agreed that they should not go out of style; just sayin that the big manufacturers would like to get rid of them.