Sell by/use by dates are put on everything to satisfy over-zealous food standards officials
Rubbish.
No it's not*.
I used to do some work on BB dates in the food industry.
Basically you store them until the point where they go mouldy or lose flavour, etc and then take a certain amount of time off depending on the product. There's not much science in it and a fair amount of guesswork or experience in knowing how much time to allow before the BB expires.
I'd expect a can to last for many years with perhaps only the flavour being affected.
As advised above, sniff it, taste it – if it doesn't taste off then it won't be.
And yes, I would eat it myself, with a plateful of chips smothered in salt and vinegar and the juice from the salmon. Haven't had that for years…….
*I'd perhaps reword the quote to read
Sell by/use by dates are put on everything to satisfy idiot consumers who've lost any ability to tell whether food has gone off or not