but French will take years for sure
No it won't. Why is this attitude so common with people always expecting to be handed out stuff...
But given that he has a 451 WITH a job offer might mean he has a very long way to go with english itself, so learning another language doesn't seem to be prudent.
There may be a CEC specific draw before July (I fully expect there to be at least a few). But given that there haven't been CEC draws for a few months, the scores will take a while to drop to 451. He may get lucky, but his best bet is to max out english scores and hope there's a draw soon enough so that scores get down to 451 before he leaves. Unfortunately, the likely scenario is he will have to leave
temporarily but will be able to apply for CEC when scores eventually go down. Although to stand a realistic chance, he should think about how he can get his scores significantly higher.
Question for you: Do you know why his closed work permit is expiring? Is his company unwilling to extend it?