Well it's been a while since I've had f.w. but, in the years that I did I can't think of a single time a cory dug up a plant. They do sometimes investigate around plants for food etc but Ime they don't mess with them much. Doesn't mean it can't happen but, I've never seen it.
Hth
chris WELCOME TO AC!!!!
Yup, cory's nose around in the substrate all the time, but unless the plant is very shallowly planted, there's no chance of cories up rooting even small(not tiny) plants. I've never had a problem w/ mine.
Mine certainly do not. My gourami however, is very good at it. Often the rooted part of some stem plants can rot away and be very easy for any fish to uproot and since cories are the ones playing at the base they could certainly get their fair share of the blame.