Plesk is preparing it's biggest update ever. They're calling it Plesk Onyx. It's got a lot of neat features (Docker, Git, Windows Server 2016, resources limitation, DNSSEC etc.) we would like to use as a webhoster. Our customers already are asking for it.
More information about Plesk Onyx: https://docs.plesk.com/release-notes/17.0/whats-new/
Can you make WHMCS compatible with Plesk Onyx?
However, fundamentally Plesk Onyx is still Plesk, and is compatible with WHMCS using the Plesk module.