You're comparing two different things. If/when Bonds breaks the HR record, it would be like someone breaking Gretzky's scoring record. And unless he breaks the record in San Fran, the fans sure aren't going to cheer him.
Modano's record would be like a Canadian player setting the record for most homeruns by a Canadian.
The league should make some sort of announcement, but to get bent out of shape over this is a little much. But, there's no such thing as an underreaction around here.
For a league wanting to grow the American Market, this would be a good time to showcase that. Whether you hate or love Modano, it should've been acknowledged.