Would add that H&C doesn’t prevent deportation and although that was always the case we didn’t see the government take action to deport those with existing H&C cases until last year. I would not recommend your parents remain in Canada until they qualify for removal. I would suggest meeting with an immigration lawyer for an opinion about whether withdrawing their H&C application while they still may be able to visit Canada for a few years may increase their chances of visiting Canada in the future. Would add that if both your parents are alive that also decreases their chances of H&C approval and H&C is not a way to circumvent PGP and so H&C for parents can be difficult to obtain and has become more difficult. H&C approval in general is harder to obtain these days as the government is clearly attempting to limit who gets approved.