Good news!
On Sep, 18 during the SIG community call, PnP Team shared their plans on PnP Sites Core library and PnP Core SDK.
“PnP Sites Core v4” library and “PnP Core SDK v1” with .net core support (.net Standard 2.0) – expected in December 2020!

PnP PowerShell v4 for SPO library built for .Net Standard 2.0 / PowerShell 7 will be released in Dec 2020 as well.