Did I kill my ESP8266?
Well if it doesn't work then it doesn't work so a safe bet is that chip is damaged.
I found this document. It states:

VBUS pad and jumber can be used to provide 5V to VBUS. By default VBUS is connected to 3.3V; certain USB devices may have issue with
this.

So I deduce that this is connected directly to 3.3V rail of the chip. Providing 5V without opening the jumper (cutting the trace) is the same as putting 5V at the 3.3V pin.

3.3V. Power pin of the shield. Do not supply 5V to this pin - MAX3421E won't be able to detect devices on VBUS and may also be
damaged!

Apparently the &quot;proper&quot; way of doing things is to actually unsolder that jumper or cut the trace.
Sorry.