Could an El Niño this year match an 1877 event that killed millions?

It is not the same world.

Food distribution networks exists, so local lost crops may or not affect food availability (economy will be different) in most regions.

Also it will be different in absolute values, the difference with the average may be the same (or higher), but the average sea temperature now is higher, and cross thresholds that push us further into positive feedback loops towards global warming. And things don't go back to previous levels.