It`s always the best decision to update to current working emunand as long as it is possible
just imagine, nintendo releases a new firmware in a couple of days/weeks/months with a new encryption and it won`t work with gateway emunand for several weeks/months again and then you want to play something, that requires 7.x encryption, but you either have no emunand or it is still on 4.x ... so what do you do then? you have to wait weeks/months for the new gateway update
so my suggestion to anyone, who is not on latest emunand firmware already: better be safe then sorry and do it now
don`t forget to follow a guide to do it right and not screw up your sysnand