Well, as people are having questions about why some are getting NOIs and others are not (despite meeting the OINP eligibility criteria). I guess, this is worth mentioning:
A. Ontario’s Express Entry Human Capital Priorities Stream application guide has this mentioned on page 3:
"Disclaimer
Please note that applicants who meet Ontario’s stream criteria may not necessarily receive a Notification of Interest. Ontario cannot guarantee that applicants will receive any particular result or benefit as a result of meeting its criteria."
Link: http://www.ontarioimmigration.ca/prodconsum/groups/csc/@oipp/documents/document/oi_en_hcps.pdf
B. From the pool of EE candidates meeting the OINP HCPS minimum eligibility criteria, maybe Ontario sends NOIs to those with higher program score i.e., the main IRCC selection criteria for FSWP & CEC (check page 28 of the guide):
Link: http://www.ontarioimmigration.ca/prodconsum/groups/csc/@oipp/documents/document/oi_en_hcps.pdf
And maybe, it's based on the six selection factors for FSWP, and those with higher score (out of 100), are sent NOIs first.
http://www.cic.gc.ca/english/immigrate/skilled/apply-factors.asp
So, if someone compares these basic program scores (not the CRS), maybe, we can understand if Ontario is using this as a selection criteria for sending the NOIs. In demand occupations could be another possibility, but there is no mention of it, anywhere, so seems unlikely.
Anyways, if candidates can share their basic program score out of 100, those still waiting for an NOI can find out if there is any correlation and/or a pattern (just an idea).