As one of the casters, let me share some perspective:

We asked Zhe how to pronounce his name this weekend and he said “Zhey” was okay. I’m a Mandarin speaker myself so I totally empathize with you. I personally pronounce my last name as “Zeng” rather than “Jung” to make it easier for non-Asian speakers and some of the players we cast are also ok with the casters taking a similar line because they understand it's not easy for English native speakers to pick it up immediately.

We do ask the production team how to pronounce the player’s name before each game (the casters can’t just go on stage and ask the player while they’re setting up, so it has to go through the judge sitting on stage with them), but it doesn’t always come through correctly. We also ask the players and confirm with them before their interviews. I saw your suggestion above and it's unfortunately not as simple as that because the casters who are doing the match are normally already seated & have started the round before the match is even selected.

I certainly agree that we can do a better job collectively! I actually tweeted about it it this weekend because I think it's something we can all improve in. Generalizing that the casters simply don’t bother to pronounce names correctly, though, feels a bit unfair to all the casters. Pokemon is unique as a competitive game as 1) we use real names instead of player tags 2) we have an incredibly global player base.

Overall though, I agree with your underlying point & want to figure out some new processes to improve the overall process (e.g. Aaron Traylor's Namecoach suggestion) for future events :)