I don't see any pics attached to this post, so I can only generalize. Basically, all clubs with black faces will show wear if abrasives get between the clubface and the ball. It's almost always noticeable on fairway woods and hybrids, but I've seen it on drivers of players who practice with range balls that aren't clean. One great player in my area had an R11 with a small spot worn down to the bare metal from all the practice he did. So it does happen on drivers.
I will still likely pull the trigger early on with the M4, but it's just a bit concerning to see so many folks reporting issues with the M2 iron face then in the first tournament I'm watching in the new year seeing that. They're not alone - other brands have issues too. Feels like TM just needs to tighten up on design/quality control a bit.