The SVG is probably parsed by a different library or different module at least and might have exploitable bugs. Still, the js would likely be fed to the same engine. It might not be impossible that something gets mangled or the context is different.

But mostly this smells like a fantasy article. No mention of which exact browser, what the mechanism is and, in particular, no sample code. And as a bonus the bs blanket term of "adult sites" which makes this look more like fear propaganda.