Starting August 1st, 2020 Microsoft will turn off ability for creating or running SharePoint 2010 workflows in Microsoft 365.
As from November 1st, 2020 all tenants will be affected by this change. Meaning that you will no longer be able to run your SharePoint 2010 workflows on your Microsoft 365 tenant. Below is the official statement from Microsoft:
Please also note, that support of running SharePoint 2013 workflows on new tenants, will also end in November 2020. Meaning the ability to run these workflows may also end in near future.
How am I affected by this?
Well, if you have always worked in the new modern way of using SharePoint and have already converted your flows to Power Automate flows, you do not have to worry.
This change will probably (yes, read probably), only affect SharePoint sites that are running in classic mode.
If you have been migrating your SharePoint sites from an On-Premises version of SharePoint to SharePoint Online, there could be a potential risk that your sites are running SharePoint 2010 workflows. So, start looking for workflows running at your SharePoint sites that are running in Classic mode. For any standard SharePoint workflows, 2010 or 2013 based, you should start converting them now.
Please note, this change is only affecting workflows running in SharePoint Online.
Other Notes
Although I have not seen any announcement regarding the retirement of classic sites support and Task lists. You may want to look at your classic sites for the use of “Task” lists. If you have task lists that has the “e-mail notification” setting enabled, this may also be affected by the retirement of SharePoint workflows. The same may also apply to standard SharePoint approval flows as they all seem to rely on this feature.