There is a reason Yoshitsugu Matsuoka is the protagonist seiyu in like 30% of recent anime. And Haruka Tomatsu starred as herself in a live-action drama about voice actresses as a mentor to the main character... I’d be surprised if something like that happened for a non-Japanese dub voice actor.
That's a stretch... you can only say it is foreshadowing if you can show what elements predicted future elements before they actually are released. Foreshadowing isn't something you can reliably identify in retrospect, because you know what happened and you might just be picking out things that look like foreshadowing because you already know what happened.
There is nothing wrong with different hair colors in virtual worlds. Hopefully in the future, Japan will get beyond its crippling conservatism and allow different hair colors beyond black and dark brown (some schools don’t even allow non-black hair at all).