The local public schools in AZ that I've heard about are doing what you described, although some needed 1-2 weeks to train their teachers to run online classrooms. No impact on grades unless it improves the grade. So basically optional. The charter school my kids attend rolled out online assignments Monday. They have 1-2 Zoom meetings with the kids each day. My kids have enjoyed it and are doing 2-4 hours of work per day and staying on track with what they were doing before this all started. The teachers are closely engaged and it looks like >90% of the kids are participating. My daughter's teacher is logging scores daily and updating the grade book.