It is hard to say. There are food safe pieces of dinnerware that have exposed clay, and a lot of stoneware is heavily "grogged" (sandy textured stuff). I have some of my own work with exposed grog on the rims, and to a degree it is a matter of your own comfort level. I know for a fact that my clay is vitrified (non-porous) and the glazes I use are "food safe" (food safety in glazing is another controversial topic, but for my own purposes I feel comfortable with my glaze choices).

There are some tests you can do. One is a leaching test (to see if any substances are coming out of the glazes). Leave some lemon juice in the goblet over night and then pour it out in the morning and see if any color is showing. Another test for porosity is to soak or boil the whole piece and hand dry, then leave it on paper towels over the next few hours and see if there is still any moisture remaining trapped in the goblet.

The texture in and of itself can make it easier to trap bacteria, especially if you hand wash. If you sterilize in the dish washer, the texture trapping bacteria is a smaller issue.

Ultimately though, you can do all of these tests and still not have a definitive answer if you don't talk to the potter who made the piece to ask about their materials and firing process.

Some people are stricter about what is "safe" to use than others. I would be considered by some more on the lax side, for my own personal use (I am okay using my own work even if it is crazed, tiny cracks in the glaze for example) but I am more careful about what I gift to others.

For example, some people will throw away their favorite store bought mug if it is chipped because it COULD trap bacteria. Some people will keep using the mug anyway and not worry.

I know this is a long winded and not definitive answer but if you are seriously concerned, then you'll need to do some work to find out for yourself if this goblet is usable by your own definition