Upsampling before processing ... do it whenever possible?

Hi - I noticed some of my plugs upsample before processing (UAD-2 cards, Melda plugs) … Rookie question here: is basically all processing subject to aliasing, and therefore all things being equal we should upsample before processing (i.e., before running through an EQ, comp, etc.) if our computers can handle it?

Thanks for any advice!

Some say that you can improve the sound of a mix by upsampling the whole project to 96kHz (assuming your tracks were all recorded at 48kHz for example). Try it and let your ears be the judge.