According to Ryan Rigney, aka Riot Cactopus, Riot's Communications Lead, they, "aren't telling anyone to avoid saying "hong kong." We'd just rather the team be referred to by its full name. There's been some confusion internally about this as well and we're working to correct it."
So it seems that there was just confusion amongst casters about whether or not to say the name, no conspiracy, no forced censorship, just honest mistakes since people can flop back and forth on the name. That isn't to say the casters are to blame, the issue is highly sensitive and it makes sense to be extra cautious with how things are handled.
IT also notes that Riot's official stance is that it is referred to in full as Hong Kong Attitude, so if anything the HKA part is a bigger slip up.