I don't think MS will have an issue with servers that would last more than a few days, if that (heck they have had one outage, if that that lasted more than a few days on 360 and even that didn't affect all users). I am sure you can agree that MS own the server market worldwide (software wise) so this is their bread and butter, not a part time hobby
When the servers are gone argument - People were up in arms when EA or some other company turned off servers to a 5 year old game or something. In practice very little happened and it probably upset a small vocal minority, who just moved on and played a newer iteration of their favourite game.
This is a mass market device, it will please the majority and niche cases like you describe are a non issue for people outside of this forum imo.
rp2000