The diamond line told you this?

I remember reading some fine print about stays during "special events" or something like that. Here is what I got with a quick prompt:

What we know about IHG’s guarantee + exceptions For “top-tier” members (Platinum Elite / Diamond Elite), IHG guarantees one guest room if you book at least 72 hours before arrival. BUT — there is an important caveat: that guarantee may not apply “during special events that result in extraordinary demand,” at the hotel’s discretion. That means if there is a “big event” — something that drives heightened demand (festivals, major conferences, holidays, big sports or cultural events) — IHG hotels may choose not to honor the guarantee.

According to a local “What’s On” guide for 2026, April in Sydney features a mix of school holidays, the autumn season, Easter celebrations, and commemorations of ANZAC Day — which often drives local travel and stay demand.

April 2026 in Sydney already has many overlapping demand drivers — holidays, school breaks, cultural festivals, conferences — which places it in the kind of period hotels might consider “special event / high demand.” Therefore, it is plausible that an IHG hotel in Sydney could decline to honor the “guaranteed room” benefit during part or all of April 2026.