There are three ideas here that need to be considered. Taking them in order:
First, this is prescriptive of how we choose who to tell confidential matters. Let’s be honest, we should know better, but we have all slipped up and told a secret to someone we thought “wouldn’t tell our secret” even though they had told everyone else’s. Don’t be silly: if a person will tell you another person’s confidential matters, they will tell yours. Do not tell your secrets to the gossip. Do not give fodder to talebearers.
Second, we need to differentiate between matters that should be concealed and matters that cannot be concealed. If I tell you that I have a weakness for chocolate chip cookies but ask you to keep that concealed, you should honor that request. If I tell you that I intend to rob the Walmart and steal all the chocolate chip cookies, you not only should tell others, you must. We keep failing on this, it seems, in many Christian circles where we keep things secret that need exposed. A “matter” in this case is either a situation under discussion that will come to light eventually, or something internal that does not come to bear on others.
Third, talebearers are those who spread truths, half-truths, and lies solely to harm another person. If they are telling what they know to be true for the protection of others, that’s not talebearing. That’s responsible behavior. Do not confuse the two.
In all, it is important to be trustworthy. It is also important to be responsible for the well-being and safety of others. This Proverb should not be taken as a plain prescription that we keep everything concealed. Far from it, this is a warning about how to choose who to tell your secrets to. It is also a caution to not publicize a case that is only half-complete. Do not let this stop you, though, from acting and speaking to protect those who need it.