I don't think that all OINP applicants gonna put their OINP progress on immitracker website. Some people won't know such tracker exist. While others will choose to track their PNP progress on the provinces' website.You’ve provided one possible reason but .. as I checked immitracker for OINP case status and noticed 2 interesting facts...
1) for July 12 and later OINP
NOIs, very seldom NOI with 450+ CRS are accepted & submitted by far, seems people with 450+ are hesitating & observing the trend
2) for May 31 NOIs most were approved with very few DIP; however for July 12 NOIs, no nominations issued yet but many on DIP stage since 1st week of August.
Based on the 2 facts above, the numbers of profiles moving from 451-600 to 601+ in this 8 days period should be very minimum. However we might see some such impact on next draw if it’s on Sep 4...
So, I would not depend on it for reflecting the actual number of PNP nominations received by the candidates.