This petitioner is male, but a female petitioner would need to provide previous marriage certificates in any case where that's the only documentation of name change. A male petitioner who has never changed their name based on marriage, does not need to submit prior marriage certificates, just the divorce decree(s) or death certificate(s)
This is one of many cases where instructions apply only when the context indicates it. Unfortunately, there are many misunderstandings due to the context not being made clear in the instructions.
Example: Petitioner with the birth name Mary Jones, married Mr. Smith, divorced him and married Mr. Harris. Assuming the applicable name change, there is no way to document that Mrs. Harris the Mary Jones on the birth certificate is the Mary Smith on the divorced decree without documenting the name change from Jones to Smith. The best way to do that in these cases is to track the name changes by submitting the prior marriage certificate to Mr. Smith.