the T&Cs reflect what the CSU offer is - entry level suite, A hotel can offer more but doesn’t have to. It will want to balance keeping higher priced rooms on the market against being able to sell your booked, lower price room. I’ve just checked looking for the Chicago IC and there are zero rooms available for my dates. When I called a few days ago they offered me a much better suite than the most basic one, I guess moving me into a better suite meant they sold my basic room for more than I paid whereas no guarantees anyone would have bought the suite,

if an entry level suite is all that’s offered to you in the call with the IHG agent you don’t have to take it. Hang up and call again in a few days as availability changes.

And I assume other people have done that - I know I certainly have.