While my iPhone is in airplane mode, it is still receiving emails. In the past, airplane mode blocked emails.?

Are you positive airplane mode is on?

I believe it is possible to re-enable wi-fi while airplane mode is on so people can use wi-fi in airplane cabins but it leaves the other radio signals such as carrier service and GPS reception turned off.

You can after you have Airplane mode ON, you can manually switch Wi-Fi to ON.

Email uses cellular data or Wi-Fi. Airplane mode switches cellular radio OFF so you have to switch Wi-Fi ON for email.

As noted, if airplane mode is enabled, WiFi and Bluetooth can then be turned on.

If WiFi and cell data is turned off, you will not get emails.