I have CLT-IAH on Friday and still have the "meal offered" indicator. But three weeks ago on CLT-DEN, I did have preorder option 4 days in advance. I had a CLT-IAH last week with no preorder (but it was on Mesa so it's not like there would have really been a choice, probably the wrap or the Spirit Airlines cheese package - never found out because we had an AWFUL F/A and the flight ended up delaying to the point many of us deplaned).

On LAX-IAH and IAH-CLT a few days ago, the meal selection opened up 3 and 2 days prior.