In cases where a URL has a trailing hyphen the FetchLinkCardService incorrectly removes the hyphen when it is parsed The hyphen is not a reserved character in the URI spec https://tools.ietf.org/html/rfc3986#section-2.2
Limiting allowed characters in the last character of the URL is came from twitter-text, but underscore is allowed on there, and Mastodon before #4941.