I would think that since they didn't come up with a completely new tier name (i.e. Titanium), the breakfast/F&B benefit will be the same across Diamonds, otherwise there would be too much confusion.

And considering how many regular Diamonds there may be in the US from the Aspire card, I can't see Hilton going back to their franchisees and reversing the F&B credit. Especially since the F&B credit likely brings additional revenue to properties, since it doesn't cover much these days.