If someone go to social media, can be identify there and make public comments, Why it would be wrong to see them to find if this person may be compatible or not? It would have save this person lot of time.
It seems voyeurism. It is probably, but a lot of social media is root on this.
And many don’t even known they are incompatible when they start a relationship. It’s latter, such as a hard case come, such as an unplanned pregnacy, or that one want to marry and the other not, that there were issues that had been ignored because they don’t speak a lot and jump on the relationship because of the desire.
So speak, and if you go on social media, you should always double check source such as simply raising the topic with the person concerned to really know her mind, position, actions.