Json Encoder/Decoder use new version of Newtonsoft.Json
As mentioned in the other comment, this was added in Feature Pack 2 for BizTalk 2016. Please comment further if this does not give the functionality you are requesting.
Coen aka Colin Dijkgraaf commented
Feature Pack 2 for BizTalk 2016 https://docs.microsoft.com/en-gb/biztalk/core/configure-the-feature-pack. Use latest Newtonsoft JSON
Newtonsoft is a JSON framework for .NET. In this feature pack, support for version 10.0.3 is included. Download v. 10.0.3 directly from NuGet.