One of the main factors would be compression molding's ability to produce large, complex parts. By compression molding, you're able to add intricate geometrical features. Extruded seals also don't have any curve or arch shape molded into their final form, which may cause them to crease up during installation. This makes it more difficult to install and may impact your ability to meet specs.
By compression molding the seal, you can add intricate features AND mold the curve into the final product. Shown in the image is an example of what this might look like with your application.
While these types of seals provide better sealing and NVH qualities, the drawback to compression molding is the higher price point. Because of this, you may need to find ways to offset those costs with more highly engineered advanced seals.