I'm the Identity Porn nominator. I checked the tagset and seeing that there was no Identity Porn tags yet seemed a lost opportunity for great marriage with a cool spin requests/fic. I feel that taking out the 'Identity Porn' bit makes the meaning of the tag less clear about the shocking secret reveal aspect, and the new tag ends up sounding more like an arranged marriage scenario where the spouses never met each other. The idea of an idenitiy porn scenario is instead about two people in love and married/engaged, but one or neither is aware of their partner's secret identity (yet).

I'd really prefer to keep the Idenity Porn bit in the tags. If you really prefer to get them listed as 'Marriage', then maybe not deleting the identity porn part could be an alternative solution.

Marriage - Identity Porn Reveal While Engaged/Married to Enemy
Marriage - Identity Porn Reveal While Engaged/Married to Unexpected Person