There were filings, they just didn't show what was claimed in that article. Those share counts were all stock options they exercised and sold immediately. Along with additional shares. Its the opposite of what that article claimed. There have been zero purchases on the open market of shares by execs at AMD. They have instead been unloading them.
Interesting optimisation results for Ryzen (lower is better, left bars "Modified Vrad" show the improvement achieved by fixing a "false sharing" issue in Valve's Source engine; this issue leading to unnecessary inter-core communication, I presume):
The poster explains the poor scaling. It is probably due to Amdahl's Law, a good portion of sequential code that is not speeded up by parallelisation.
"The speedup in the fixed section of the code is likely a fair bit higher than what's shown here."
But, yes, the case shows how easy it is to introduce a scaling problem if the programmer does not understand multi-threading and shared memory well. Luckily, the shared counter, in this case, was useless and could be removed.