If this was the case then the date would be a use by and a not best before. Best before means the timespan that the product will taste at its best. It is still perfectly safe to consume after this date and in the case of the Huel bar it’s likely to just be dryer than when it was new.
Dairy products have a use by date because they turn and will cause illness if consumed long after the use by date.
Hi Mike! I would eat one of those dry old bars, then I’d post “I ate one. It didn’t taste too bad, but there was a slight metallic aftertaste and now I feel a bit dizzy. I’ll post an update tomorrow for sure!”