Well that was staggeringly prescient.
The notion of a restricted server-side language for user scripts still sounds useful and an unfilled niche.
It seems modern microprocessors simply aren't designed to run untrusted code.
True, Java applets largely died off, but that was as much because it took Sun WAY too long to ship the "Consumer JRE", coupled with a rash of Java security issues over a certain window of time, that made people scared to enable Java in their browsers. I doubt many more people disabled Java after Spectre/Meltdown, than before.