The problem with just doing things on the normal schedule is that a lot of kids aren't available for learning during the day or won't be supervised well enough to keep to ordinary schedules (a middle schooler home alone probably isn't going to be up and logged on at 7:15!) Some of the schools around me only got 30-40% participation with trying to maintain real-time school schedules, because kids weren't in school. They were at home without reliable internet, or they were with a sitter, or they were at Grandma's, or they were home alone with siblings and didn't wake up for normal school times. In our distance learning surveys, a large chunk of our families expressed a strong preference for asynchronous lessons, so parents could supervise learning on their own schedules rather than trying to find caregivers willing and able to do so while the parents worked (or slept - we have a couple of second-shift families who let the kids get on the parents' schedule when everything else stopped).
The other issue is the workload for teachers who are going to be teaching both in person and online. Uploading new lessons a couple days a week, on a block-type schedule, for the families who have chosen remote learning is preferable to teaching a full day and then also formatting, editing and uploading daily lessons for the remote group. Obviously this doesn't matter so much for districts that aren't offering anything in-person, but most around me are leaving it up to the families. So teachers are going to have to do both in-person and remote lessons.