About a 1% chance of getting the meal.
End of the story:
When I got to the gate on my flight back from SFO to EWR, I asked the ticket agent if I would get my Kosher meal. She checked and found out that the CSR at United only put in my request for Kosher from EWR-SFO (where I was not upgraded and not entitled to a meal) but forgot to put it in from SFO to EWR. She said that had I called in 24 hours before, she could have gotten it for me. She called the gate to see if they could push it through but of course they couldnt.
She gave me some useless meal vouchers - useless because only restaurants take them, and they dont have anything kosher.
Of course, as soon as I landed, a called the CS voicemail and left a message, also sent an email feedback. They called me back today and sent me $100 United Online Travel Certificate.