It feels like they are releasing the information as it comes in, so I suspect the age weighting was done after the first release. I asked the question about the 45 or 60 day follow up on Been's show and NP said they would be getting more data on that, so the analysis could continue to change I suppose.
I recall that Dexamethasone used some age weighting for approvals too and it was accepted and ultimately given EUA.