My understanding is that the manufacturer of the vaccine didn't apply for emergency approval- they are letting it go through a longer process by their own choice.
There might be perfectly valid reasons for this- I am not sure to what extent the government could or would want to force it to fast-track.
The manufacturer didn't apply for EUA because the European trial was a mess, and there was basically no chance of FDA approval based on the data they had.
The FDA is already reluctant to use trials from jurisdictions that may be very different demographically. When the trials are marginal, confused, and confounded, the chance of a FDA approval become negligible.
If the AZ US trial pops out good data, you can expect a speedy EUA application.
Probably the same reason why the manufacturer hasn't requested EU approval of the Dutch plant where they manufacture vaccines exported to the UK. That is, to make more money.
There might be perfectly valid reasons for this- I am not sure to what extent the government could or would want to force it to fast-track.