It is not. However, be aware that it could create a major complication later on for the spouse on grounds of misrepresentation. When a person chooses a spouse to be “non accompanying” simply to get a higher score (score manipulation), this gives rise to a situation where the spouse would later have to be sponsored.
When you sponsor your spouse at a later date, the IRCC may enquire as to why the spouse wasn’t originally not included on your EE application. When you choose your spouse as non-accompanying, you need to provide the reason to do so.
When you sponsor them later, the IRCC evaluates whether the sponsorship is reasonable in light of the reason you “originally” provided. If they suspect that you chose your spouse to be “non-accompanying” simply to manipulate the scoring system, the sponsorship application may be rejected.
If the spouse applies for EE independently later on, the same question arises. In her EE application, the spouse will have to disclose that her husband is in Canada and is a PR. That is a question on the application.
When her application is evaluated, she might be questioned as to why she wasn’t included on the original EE application of her husband.
My attorney had given me multiple warnings about this when I had chosen my spouse as “non-accompanying”. Which is why, the minute I got confirmation from her employer that she can be moved to their Canadian office, I added her to my own application.
To be clear, my attorney has dealt with cases where spousal sponsorships or independent EE applications of spouse at a later stage have been denied because of suspected misrepresentation by the IRCC. To prove that you had a legit reason, you have to provide evidence and quite often that is hard to provide, especially when you did not have a legit reason in the first place to keep your spouse as “non accompanying”.
Hope this is clear now. It is not an “offence” to have spouse as “non accompanying”. But it is certainly grounds for rejection of spousal sponsorship or independent EE application of the spouse on account of misrepresentation. Misrepresentation has serious consequences and your spouse may eventually have trouble emigrating.
To be clear, not everyone gets rejected if they file spousal sponsorship later on. Many applications do succeed. But there are also some which do not succeed. There is no guarantee of how this plays out. If you are willing to take the risk of your spouse getting stuck in a different country, you may go ahead and make your “non accompanying” decision simply to manipulate scores. It is your choice - and please make an informed decision rather than asking snarky rhetoric questions.
Hope this helps. If you’re thinking of score manipulation by flipping between “accompanying” and “non accompanying”, please consult a proper lawyer to understand the consequences. I don’t suggest you do this via online forums or via “immigration agents”. You need an actual attorney for this kind of decision. Someone who can represent you in case an appeal needs to be filed for rejection of spousal sponsorship later on.