Is this what you are trying to do - if not, please explain what you are attempting to do (not just what doesn't work)
bin _time span=1h | stats count(eval(eventDay==curDay)) AS cv count(eval(eventDay!=curDay)) AS ce by _time, uid
Your second stats will not work. Because after 1st stats there will be only cv and uid fields available in results.
bin _time span=1h | stats count(eval(eventDay==curDay)) AS cv by uid
The second stats required eventDay,curDay,_time and uid. That's Y you are not getting any results.
| stats count(eval(eventDay!=curDay)) AS ce by _time, uid
Please share the logic or steps for your search. So we can help you on.
KV