I don't understand the point of Applications getting rejected when applied together. If IRCC is going to reject an application under such a clause, then why provide such an option to apply together.
To me, it looks like a myth as no one knows a definite answer.
Honestly, I've stopped looking at IRCC process logically. The entire process has so many loopholes and people exploit them left right-center. It would be so easy for them to give an option to choose if they are studying to qualify for PR. Let candidates explain the truth and then the VO can decide if the candidate has good enough points to qualify for PR. But, they choose to make applicants lie that they will return to their home country. Zero logic as for someone who decides to do fraud will do it anyway even if I say that in my SOP.