I think that's the developer's fault. The holders deserve the swap service that will be last forever. It's not fair for the old holders that didn't get any information regarding the swap will get useless token.
MZG was a garbage coin but it's not for pundi.
There are some services that gave the old holders ability to swap its token forever.
The team who has been giving deadline to do the swap just like cheating its old holders.
For various reasons, we may not know about the exchange of tokens, and the project team sets a short time for this. Indeed, it would be fairer if one could exchange them at any time. Otherwise, it looks like cheating. Now there are already more than 9000 different types of cryptocurrency and this must be taken into account.