Sure, extra precautions are nothing to appologise for but if you are after a minimal approach with pragmatic risk assessment the voltage dividers are not a must have.
This is difficult to achieve since
System.sleep() will apply the respective pull-resistors depending on the trigger edge. So if you don’t want an internal pull to be applied you’d need to trigger for CHANGE.
Deep sleep always has uses the internal pull-down.
A related comment/proposal exists in a pending firmware issue
However, as long you are not using A3 or A6 (aka DAC) as wake pin, you don’t need a voltage divider as all pins (apart from the two) on the Photon/Electron are 5V tolerant (for a short time even with attached internal resistors).
If the internal pull-resistors are only attached for the sleep periode and after applying 5V the device immediately wakes and reverts to
pinMode(pin, INPUT) - either by having had it assigned before Stop Mode sleep or by default after deep sleep - you should be good.
When opting against the voltage divider make sure you don’t
analogRead() that pin but rather use
digitalRead() which will again accept 5V and rid you of the need for a voltage divider.
System.sleep(SLEEP_MODE_DEEP, 3600); // deep sleep for 1h or till RISING edge detected on WKP
System.sleep(D1, RISING, 3600); // Stop mode sleep for 1h or till D1 goes HIGH
// for that version make sure you either don't set pinMode() or
// exlplicitly set it to pinMode(D1, INPUT) any time before sleeping
// or immediately after the System.sleep() call where the code will follow
// on after wake