MP1584 EN pin voltage
No, it is not a problem because it is a schematic in the datasheet. If you cannot trust that then IC manufacturers would have big problems.

Also, applying a "hard" 10 V, which can deliver a large current at the EN pin might indeed damage the device (I doubt that though). But in this schematic this 10 V is "soft" it cannot deliver much current. So if something on the EN pin would start to conduct, only a small current can flow and nothing will be damaged.

You can check this, build the circuit and apply a Vin which will result in 10 V at the EN input. Now measure that voltage. If it is 10 V then the EN pin can withstand more than 6 V. If the voltage is much below 6 V then the high value of R5 saves the day.

If you're worried, you can adjust the values of R5 and R6 to get a maximum of 6 V on the EN pin. Then watch that EN will be high enough at the lowest Vin.