Whenever you’re working with WordPress and third-party APIs, there’s always a chance that you’re going to run into issues where the third-party API is not prepared to handle certain characters that exist in a permalink.
Depending on one’s permalink settings, though, this may or may not be an issue. For example, you may have your permalinks set to something like ?p=123 for each post. In that case, it’s not much of an issue.
But if you’re using “pretty permalinks” and your permalink includes something like a trademark symbol or a copyright symbol, then it may cause problems whenever you’re communicating with said third-party API.