[Clamchop]

This might stem from noncount noun rules rather than any particular trend for the word "pants".

Typical example is the word _water_. It is noncount except when talking about types of water. E.g., this year we introduced a vitamin water and an energy water to our line of beverages. By extension, you can pluralize it: we introduced two new waters this year.

I don't disagree that pants might be slowly becoming countable, just noting that the particular verbiage of "a capri pant" or whatever can be produced using the usual rules.