You can work for them but you can't double count work experience for the same period. So you either claim points for your work experience in Canada or for the work experience outside of Canada for the same period. You can't claim both.
Please do not rely on AI for immigration advice. It's not at the maturity level to give good advice and picks up to much open source info that is misleading or even flat out wrong (e.g., making up stats, making up immigration rules that don't exist). It will get there eventually but do not use...
If you want to apply for citizenship for them, they have to travel to Canada, land, and formally become PRs. They won't qualify for citizenship if they just have the COPR but never traveled to Canada to become PRs.
You need an excellent immigration lawyer. I believe this feedback was given when you posted pre-PFL. This situation is far too complex and unique. You need very good legal representation. Hope you find a path forward.
But you still won't have an approved LMIA or an approved LMIA-exempt work permit. This is really straightforward. The answer is a no. This isn't a future looking response.
Speak with an immigration lawyer. This has the appearance of trying to game the system since your sibling moved back only a month ago and for the sole purpose of you being able to gain the 15 points. And now you're trying to back out of that.
This is way above the paygrade of this forum. You are dealing with complex legal and custody issues and need to consult with a very good immigration lawyer (if you're not doing so already).
I'm not a lawyer. But IMO very possible IRCC may not feel this is enough without a recent authorization...
Whether he will get PR along with his wife (or needs to be sponsored separately) will depend on whether he was included as accompanying or non-accompaying in the H&C application.
There is no legal or professional advice offered here. We are all normal people like you. If you want legal advice, you'll need to hire a lawyer.
Order GCMS notes now. They will take a while to arrive but should indicate what is at the root of this.
There could be any number of reasons why...