It's a bit surprising that the article didn't mention ensuring constant time algorithms are used. If latency or the emissions of the CPU (etc. externally observable) are data dependent on something secret, that secret might leak through the side channel.

One way to combat these side channels is to use constant time multiplication, loop conditions (including functions that might return early, like memcmp), etc.

Is it possible for Rust to have any new or surprising mechanisms that cause loss of constant time execution?

(Of course also other aspects can leak than the CPU instruction execution latency itself. For example cache effects might be measurable.)