I'm about to replace the hotend on my Sovol and it occurs that it would be great if rather that cutting and joining wires it would be great if it were possible to unplug the old an plug in the new. Probably a stupid question but does anyone know of any sort of standard to achieve that.
one way would be to reuse your current hotend heater cartridge and thermistor.
Just remove them, install the new hotend and put them back in
Now why didn't I think of that, not the sharpest knife.
BTW did you notice that on the youtube vid you referenced, the hotend was for an Artillery Sidewinder which has the neat feature of plugs and sockets on the hotend wires.
Yes that's a nice feature 
I got this shrinking net wire sleeve thingy
With that a cable change is done in a minute
Yes it does make the cable bundle tidy, actually my Sovol SV01 has this sleeve as stock.