I just found that on the SQL Server 2012 MSDN documentation for binary and varbinary types, they mention the following at the end of the article:
Conversions between any data type and the binary data types are not guaranteed to be the same between versions of SQL Server.
I noticed that this does not exists in the previous versions of the article for 2005, 2008, and 2008 R2. I searched around online but didn't find any exact explanations that satisfied my question of "WHY?". (Which is the question I have here.)
The project I am working on needs to store data as varbinary(max), but based on this little note, I am afraid if I need to move the binary data and then convert it on another SQL Server version that it will not match the original data converted to binary, so answering this question more in depth would be a great help.