Irrelevant. That's the problem. The terms say X so they need to honor that. There is no verbiage about when you ask etc. That's the literal reason you spend 60 plus nights or X Dollars a year... to get certain benefits. When people allow excuses like I didn't ask at arrival etc, it makes them more bold in breaking the rules in general. The benefits and terms are already really hostile enough to the customer, so in the ways it is clear they need to honor that. Full stop. I'm not saying you can't and shouldn't be gracious in working with a hotel when certain things are difficult for them or you don't really need or want etc, because plenty of good hotels certainly still go above and beyond. However if at the end you really need a benefit like late checkout and it's one of those that's very very clearly spelled out, then if push comes to shove, they need to give and if they don't, you need to elevate it.