I also wasn't familiar with this terminology:
> You hand it a function; it tries to match it, and you move on.
In decompilation "matching" means you found a function block in the machine code, wrote some C, then confirmed that the C produces the exact same binary machine code once it is compiled.
The author's previous post explains this all in a bunch more detail: https://blog.chrislewis.au/using-coding-agents-to-decompile-...