I think it uses the media tag so it can show a page preview? Just a guess.Irrelevant. if I hard code a URL as a URL, it should stay a URL. Its not Media, its a URL.
And I could see it being a "feature" when you just paste the URL into the body and go, but when you explicitly specify its a URL it should stay a URL. Full stop. Because obviously arbitrarily rewriting it breaks some browsers.
Found it. Ublock Origin. Because of the media rewrite instead of a URL, it thinks its an ad and blocks it. SMH