It may not be a direct entitlement but I've seen them at all 3 property types.

What I tend to see with upgrades:
1. It varies radically and seems to be largely controlle by individual properties. I sometimes think about starting a thread it 'out' properties that consistently turn down Diamonds for upgrades.
2. Strangely I have more luck when I'm staying on points. I was told by one manager its sort of an unspoken rule.

Overall though I have to say that its rarer than I would expect but its not something you can count on at any chain. My best luck is IHG at Holiday Inn Express properties (3 out of 4 more or less) but my worst luck is also at IHG at the Holiday Inns (often have a very very small inventory of nicer rooms). I've certainly seen upgrades but overall Hilton doesn't have the success rate I used to see as a Plat a Marriott either.