AFAIK the coins were never pre-funded. The funds were always added after purchasers received their coins. This is no different; it's just you funding them upon receipt instead of Mike funding them.
To be fair, there's a difference between an unfunded coin that I intend to fund with the original buyer's funds on hand but just haven't done so yet, and an unfunded coin that I explicitly have no intention to fund.
All else equal, one's likely to be considered worth 1BTC more than the other.
There are some advantages to the latter. For example, I don't have to force users to use expensive shipping options to keep a grip on unfunded coins making it into the wild. If self-fund coins get lost, the loss is limited to the physical coins that got lost, and not any BTC.