After Meltdown and Spectre, many researchers warned that increased scrutiny on side-channel meant more attacks will be found, so the discovery of "Variant 4" is not a surprise. More variants will be found as chip makers update their designs over the next few years to fix the issues.
Mikhail Davidov decided to see what it would take to develop a process to manually decapsulate chips. After months of work, experimentation, and trial and error, he succeeded.
Much like Spectre, BranchScope is an attack that focuses on the processor's branch prediction system. That doesn't mean the processors are hopelessly vulnerable. It just means that as more researchers start exploring various features in modern CPUs, more issues will be found.