BizTalk Orchestration does not appear after deployment

I had a weird scenario where Orchestration was not appearing in BizTalk Administration Console after deployment through Resources > Add BizTalk Assemblies

The reason was the following missing entry in AssemblyInfo.cs. Actually the project template was copied from another BizTalk project and AssemblyInfo.cs was removed during the process. When we set assembly properties, VS generates the AssemblyInfo.cs but missed the following entry required for BizTalk assemblies

using Microsoft.XLANGs.BaseTypes;
using Microsoft.BizTalk.XLANGs.BTXEngine;

[assembly: Microsoft.XLANGs.BaseTypes.BizTalkAssemblyAttribute(typeof(BTXService))]

When tried to deploy the project from VS, its give the following error which hints about the actual issue

Assembly does not appear to be a BizTalk assembly, and cannot be deployed to the Configuration