It's official – the Samsung Austin Research Center (SARC) has been shuttered as rumored around a month ago. As a result, Samsung's latest Exynos 990 could be the last, or one of the last, chips from the company to feature its custom Mongoose ARM-based cores.
https://www.notebookcheck.net/Confirmed-Samsung-shutters-custom-CPU-team.441142.0.html
Understandable, the team hasn't been delivering, and ARM CPU performance beyond Apple has also reached a "good enough" level. Apple's efforts yield 2-3 years additional future-proofing and...well, just bragging rights, before ARM based Macs are developed.