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.