Is the intention here to force improvements to recharging capabilities? If i remember correctly, the rules allow competitors to switch cars entirely during the race, not just recharge or replace the battery. Seems like that undermines as expectated research / improvements to recharge technology.
That said, there's people who complain about F1 cars not sounding the same any more like they did back in the early 2000s (with the classic V10 engine), so even if the FE cars get modified in some way to change what they sound like there might be people complaining. Would be funny if for broadcast they replaced the FE sound with '60s V12 sounds, though.