2020 does seem a very short shelf life even for things with an expiry date. There is every chance that the date does not refer to all the items in the kit but the one that is closest to expiry so I would suggest having a look in the kit, which will also familiarise you with the contents, and replace that one item rather than the whole kit. Expiry dates tend to be on sterilised items which may come into contact with open wounds or as above ingested or absorbed, and beyond the specified date may no longer be sterile, so best practice would suggest when you are checking your first aid kit to replace any expired items. This also applies to AED's as the batteries and pads have an expiry date.
You'll probably find many items in your kit do not have an expiry date.