The meforshim in chumash clarify what it means that yaakov avinu lo meis. If he was really alive he wouldn’t have survived the embalming and burial for long.
Years ago a chabadnik told me “yaakov avinu lo meis” and used it to convince em that the funeral we all saw was a farce. Nope. Shor shachut lefanecha.
Why don’t we dig up the rebbe and find out if he is dead or not? Let’s settle this once and for all.