To me it’s really a day by day and monitoring the situation, FedEx has one the largest fleet in the US, but things can change quickly.
Yes there are surges in medical equipment shipments however most of those are mainly done by the army and domestic airlines, you do have the issue of increase of private online purchases which some do ship via Fedex.
At this time Fedex still accept animals they just no longer can guarantees arrival time of 10.30 for overnight shipping.