You are right about NOI not being equal to nominations, but NOIs of one year precede the next years nominations. Also, in 2020 they sent 9,082 NOI to candidates in the Express Entry pool.If you check 2020 OINP year end results, out of the 9k NOI's they nominated around 2.3k only under all express entry streams which means almost 7k NOI's didn't receive nominations. Rest all of the nominations went to their paper based streams and I am sure 2021 results will be the same.
NOI's is not equal to nominations, OINP can decide to just focus on their paper based streams for the rest of the year which looks to be the trend.
Either way, I have no luck with Ontario whatsoever. Eligible for two streams, picked by none.