I fear this is more of an overall movement towards less and less action figures.
It wasn't that long ago that the action figure aisle bled over into other aisles. Now, I find in many stores that other toys are bleeding over into the action figure aisle.
Like with comic books, I just don't think as many kids are buying (or getting mom to buy) figures any more.
I’ve noticed this too. Not just putting some lines on clearance but not replacing them with anything else. Two Walmarts I go to seem to have downsized the whole Toy Department. Toys R Us seems to have more expensive figures on the “Collector Aisle” than regular figures on the regular aisle. When I do find figures there is always only a few, not like the old days when there was always plenty of figures to find.