The hotel is not required to upgrade you to a suite, but it is nice if they do. There is no entitlement for IHG Rewards elite members.

Hotel Room Upgrades for Platinum Elite and Spire Elite Members: Platinum Elite and Spire Elite members will be offered a complimentary upgrade, as determined by the hotel, which might include rooms on higher floors, corner rooms, newly renovated rooms, or rooms with preferred views. The upgrade will be offered at time of check-in, based on availability, and will only apply to the member's personal guest room. The hotel is not required to upgrade members to suites or specialty rooms. Upgrade benefits will not apply to rooms booked as a Reward Night reservation.