that TechNet forum post has nothing about .NET 4.5 compatiblity issues in it, and contains misleading information in its own.
There is basically 2 problems for Exchange 2010 on Server 2012 in that post.
1, it depends on .NET 3.5
Then someone posted a misleading instruction of installing .NET 3.5.
you can just install it without touchingt .NET 4.5 at all. Another reply confirmed this later.
So the only place .NET 4.5 mentioned in this post is wrong information.
2, it requires some roles/features to be installed, this has nothing to do with .NET 4.5 either.