So I'm not trying to be critical of educational content... but what this article is actually saying, surely isn't earthshattering news. Basically what it boils down to is that embedding SVGs with an img tag is probably safe, but expanding a user-provided SVG into your web site's code is definitely not safe.
Like I say it's fine to make an article for people who didn't know that, but framing that as an SVG problem (instead of an expanding-user-provided-HTML-onto-your-website problem) and building fear-mongering around touching SVG files as a result doesn't seem right to me.