The primary goal of EF Core 3.1 is to polish the features and scenarios we delivered in EF Core 3.0. EF Core 3.1 will be a long term support (LTS) release, supported for at least 3 years. To this end we have fixed over 150 issues for the 3.1 release, but there are no major new features to announce.
EF Core 3.1 reintroduces support for .NET Standard 2.0, rather than requiring .NET Standard 2.1 as was the case for EF Core 3.0. This means EF Core 3.1 will run on .NET Framework versions that support the standard.