> In 2001 Mark Probst implemented tail-call optimization in GCC with a separate calling convention; he lists the limitations of the then-existing tail-call optimization in GCC in section 6.4, among them: "It cannot handle indirect calls" (which would have been used in tail calls for interpreter dispatch).

Relatively recent being a quarter of century? Or at least a fifth of a century for indirect calls[1] (GCC 3.4.6 is the earliest I see on Compiler Explorer, released March 2006).

[1]: https://godbolt.org/z/vvcnn54oM

For people who passed their 30s, everything that happened after their 20th birthday is recent. For me, September 11 is recent memory, as well as the 2008 great recession.

Given that GCC was first released in 1987, that would mean that tail call optimization, including of indirect calls, has been around for more than half of GCC's lifetime. So it's indeed fair for the parent article to say that "[GCC has] had tail-call optimizations for most of [its] existence".