yes, the sizing has changed.
I've been wearing these pants for years on a daily basis. They're comfortable most of the year in the Pacific Northwest and great for most any activity. That said, they do wear out eventually and sadly there is no size even close to those I've been wearing. I'm 5'6" and about 130#. I've been wearing the Large petite because I like a loose fit. The current large mediums are about 4" larger in the hips (sending those back) than the pants I've been wearing and the mediums are a bit too tight in the waist and a snugger fit in the hips. So the difference between the medium and large is huge! All this is very discouraging for a brand I like but can only try on by mail order.