The initial Reddit post that Community Team lead Trick is responding to can be found here. Below is a response he posted to the thread.

Hey folks, I checked into this and here’s what I can tell you:

First is an important clarification: Proxy cards are substitute cards created solely by judges in sanctioned tournaments. These substitutes are allowed when authorized game cards become unplayable during a sanctioned tournament because of damage or excessive wear. Unauthorized reproductions of our game are a type of counterfeit, and we want business partners to help us in discouraging counterfeit Magic.

I know that feels crazy, that we regard marker on a card as a counterfeit, but remove the visual accuracy from the judgment – they serve identical purposes when it comes to game play.

Counterfeit cards are prohibited in sanctioned events, sounds like most people are on board with that. And based on Wizards’ Code of Conduct, we have started to ask stores not to organize unsanctioned events with counterfeit cards. And to be clear, no one we’ve communicated with recently has been suspended or punished as far as I know. We’ve talked to some stores on the difference between counterfeit and proxy cards, and are asking WPN to stores to work with us in protecting our intellectual property.

Wizards wants partners in the WPN to make sure stores are welcoming environments, not use our characters in offensive images, and any number of actions that protect Magic experiences. We don’t condone counterfeit cards, and we expect stores to respect that. WPN stores are our partners and we expect them to help us protect our intellectual property.

We know players love Magic and love playing its variety of formats, including Vintage and Legacy. Some formats are easier to get into than others and these two are hard.

-Trick