Unless they change the design, 1st or 8th batch also no difference. The BT antenna on the left joy-con is on the PCB, not external, and it is right next to the joystick's base, which is one big piece of metal (Nintendo's own advise, do not place the joycon in or under a metal object). And this on-board antenna is also positioned where your fingers may rest.
The home-made patch is to create your own antenna and run it in the opposite direction (towards the bottom instead of the top side of the joycon). If Nintendo does this, that's a change of design. Note that they cannot just duplicate the right joy-con design (which has an external antenna going to the side), since the joysticks (and the big metal base) are located differently from the left joy-con, plus the right joy-con has IR sensor and NFC.
So basically if one have all sorts of wireless signals at home, then it's more likely to encounter the problem (even on the better designed right joycon). If one doesn't and never encounter any problem, yay that's good, but don't be an ostrich and pretend there is no problem at all, ppl are all lying about it, it is not widespread issue, it's the vocal minority making so much noise to sabotage the console. Everything is fine, just call Nintendo support and you will be fine, as Reggie suggested.
