@Josh__Stephens is right, if you are scheduling Workspaces, then the schedules won't be impacted, they use "Scheduled Projects" not "Scheduled Reports".
If you have actual "Scheduled Reports", it won't just be a matter of the schedule feature not working... those Reports will all cease to function. Unless you are talking about Report Builder Reports... which is a bit of a grey area at this time... Report Builder Reports will continue to function, but I really don't know how we will be able to review those schedules one "Schedules Reports" is removed....
Ostensibly you should be able to adjust the schedule in the Report Builder plugin itself?
However, at this time, you can try reaching out to Client Care, but like @RobertBlakeley said, the sunset of Reports has been widely publicized for over a year, and since most of Adobe is currently shut down for the holidays, I expect only Sev 1 issues will get a lot of traction at this time...
However, we don't work for Adobe, and we don't know what the Sunset is going to look like... it might be like when GA Universal Analytics was shut down earlier this year, some sites continued to track UA for several months after the deadline... Adobe may be doing a similar roll-out.. all you can do is try.
Good Luck.
