What a weird Wiki. This indeed creates a board definition with the right pin mapping, but does not use Heltec’s forked Arduino core, which has crucial changes needed for the LoRaWAN library to work, which are the main point of the board.
Heltec support in PlatformIO remains bad, with only point-wise hacks and patches known. See How replicate this step from Arduino IDE to PlatformIO - #2 by maxgerhardt