I wonder if they are only recommending the Lectron adapter for Chevy Bolts. The Lectrons are known to overheat and shut off at high amperage.
Under the Lectron P/N it has this:
"Portable – conveniently carry or store in your glove box, center console, etc.",
"Measures 5.2 L x 2.5 W x 3.9 H inches",
"Rated Current: 300 Amps @ 35°C (95°F)",
"Boost Current: 500 Amps for 10 minutes",
"Some MY19 and MY20 Chevrolet Bolt EVs require a software update to ensure a successful charging experience. Please schedule a service appointment with your Chevrolet Dealer to get the latest software update",
"WARNING: Use of charge cord adapters may cause electrical overheating, ...
But that software update is not mentioned for the Tesla supplied adapter, and it refers to the limits of the station:
"Portable – conveniently carry or store in your glove box, center console, etc.",
"Measures 5.2 L x 2.5 W x 3.9 H inches",
"Rated Current: 300 Amps @ 35°C (95°F)",
"Boost Current: 500 Amps for 10 minutes",
"Charging times vary based on the power and current available from the charging station (actual range may vary based on several factors, including ambient temperature, terrain, battery age, temperature and condition, loading, and how you use and maintain your vehicle)",
"WARNING: Use of charge cord adapters may cause electrical overheating, ...
The Bolts only pull 55kw (125A), so they will never overstress the adapters, or run into limitations of the chargers. All the Ultium vehicles can pull up to 500A, even the Equinox. GM has delivered about 150k bolts in the US, so getting Lectron to support those cars makes sense. That leaves the Tesla adapters, which send the temp to the charger, for the Ultiums.