Sockets are bad news for EVSEs for a couple of reasons, but the main one centers around a NEC 2020 requirement for GFCI protection on all sockets - even 240V high current ones. Now, an EVSE is itself a smart GFCI - in fact, that's its only function, other than sending a coded signal telling the car how many amps it's allowed to draw from this power point. So a hardwired EVSE aptly meets the NEC 2020 requirement.
Also, hardwiring is required if you do "Share2" style Power Sharing to dynamically share power among multiple EVs. (which is the only way multi-EV home charging should ever be done). And hardwiring is required for 60A or larger, however if your EV is smaller than, say, an up-armored mine-resistant Humvee, you probably don't need that much charge power. (sidebar below).
Now if your permit was pulled and the work done prior to NEC 2020, you can just leave it that way. That particular socket will adapt to ANY socketable need for power - since it has neutral, it can power RVs, be split off to power 4-6 large 120V appliances, kilns, welders, compressors etc. They make adapter cables that plug into this and give you anything. (the UL listed types include appropriate fuses molded-in).
However if you wanted a hardwired EVSE there are several ways to go about it. One is to remove the lid and socket and install a blank cover plate with a 1/2" or 3/4" knockout on it. Then you can come off that with a FMC or wire whip to your EVSE. Alternately you can install the EVSE directly over the face of the blank cover plate so holes align (install THHN extension wires; install box spacer connector onto blank plate, install blank plate on box, install EVSE over box spacer connector, attach wires).
Another way is to install an "extension box" and come out a side port on the extension box and run conduit of your choice to the EVSE. This can be fairly elegant; look at Legrand Wiremold.
(sidebar) It's funny, because within the EV community this is not widely understood, and people put in 14-50s because that plug is provided gratis with their free travel charger because it's the plug at RV parks, duh... and novices see that and think it's the standard EV socket. So the novices have it installed then become EV elders and tell everyone else "do what I did (so I can avoid admitting mistake)". And this becomes a "juggernaut of wrong" and it's interesting to see it reaching government levels. EV's don't even use neutral so using 4-wire cable here is wasted. "Let's waste copper! For the environment!"
But the scary part is: a NEMA 14-50 means you will be charging at 40A or 50A nominal. Most houses do not have 40-50A of spare service capacity. A NEC Article 220 Load Calculation needs to be done for a load that large. A rational approach to EV charging starts at the NEC Load Calculation, determines what is feasible, counterpoints that against the owner's foreseeable need, and takes into account that DC fast chargers are only getting more and more available (as well as high-power level 2 destination units at malls and hotels).
