My biggest concern is that they indicate length (or lack thereof) in the string types. While there are certainly cases where the type would be a security leak, most of those the idea that they can even get to what you show is the bigger leak. Further, most databases I have seen have names that convey far more information than the mask.

For instance I would expect "email" to be a string like type. I would expect "price" to be a number. If I were concerned about the type leaking out, I would also concern myself with purpose as well and ensure my column names gave no clue as to what the point of the column is.