Its not required as you are not going to use RDBM and vision that come with R12.2 media.
but see the note R12.2: How To Create the Stage In Preparation For Installation (Doc ID 1596433.1)
If i remeber correctly i had completed building stage and installation without vision files. I guess buildstage completes but checksum will definitely give errors as some of the files are not available.
Even if you down load and buildstage with all files, while you are laying down filesystem for upgrade with existing database you will be asked to ignore database installation part.
As its a production upgrade you better go as per note 1596433.1