Common sense would dictate that with 75 Cut off for CEC draw every single candidate would have been given an ITA, I am very curious as to how 5,000 CEC candidates were invited again today. Does that mean over 5,000 CEC candidates created their EE profile from 13th Feb 2021 until 18th March 2021 or does it mean that not all CEC candidates received an ITA on 13th Feb 2021 despite having a CRS over 75 points?
Full guide
Why CEC Express Entry draws keep inviting thousands even after a low CRS cutoff
Lots of people have just finished their one year of work experience, or finally decided to create their EE profile , or had to decline their previous ITA for this or that reason
I think you did not analyze pool carefully, 20000+ people created profiles after mega draw.