On Friday April 10th Secretary Jesse White announced that an Emergency Rule was filed to extend the expiration dates for DLs, IDs, vehicle registrations, other transactions and document filings for at least 90 days after Driver Services Facilities reopen.
This extension includes the completion of school bus driver refresher classes as well as renewals of school bus driver permits.
You can view the full announcement here: https://www.cyberdriveillinois.com/news/2020/april/200410d1.pdf