If there is a butterfly cat that pupates in the dirt, I have not heard about it yet.

KC

Some butterflies' pupae hang out in the leaf matter or debris or mulch in a garden (American copper, spring azure, fritillary caterpillars overwinter in cat state, as do Harris' Checkerspots, and many moth species).

You should be fine with the landscape fabric as long as you have some mulch on top, or make sure that you aren't placing the fabric on top of mulch/debris that might be harboring pupae or caterpillars because they would then be trapped.

It's great that you are thinking about those butterflies that are in diapause over winter.