When you're traveling with small kids, this is not a "request" but a necessity. You're telling me they can't block a couple of connecting rooms ahead of time?
I know DJ had problems with Hilton, but we didn't. And from the looks of the parking lot and breakfast, they were jammed full while we were there. The first time I tried making the reservation with Hilton, it just didn't look right. Didn't "say" connecting rooms anywhere. That's when I noticed the "search for connecting rooms" symbol (sort of a weird infinity sign), and it walked me through it. At this particular hotel I had to book the same room types, which was fine.
And most people don't even "want" connecting rooms - they complain about noise coming through the door - so it would seem with a little effort this should not be a problem.