Sorry, but you’re wrong about “old” stuff. PowerPC uses speculative execution since the first CPU, the PowerPC 601 (the year was 1991!), thus it is affected by Spectre. Meltdown is Intel-only as far as we know anyhow.
Proof? From the TenFourFox developer (blog post): “Power ISA is fundamentally vulnerable going back even to the days of the original PowerPC 601, as is virtually all current architectures, and there are no simple fixes.”
The same is true for IBM POWER and OpenPOWER.