I invited heaps of people to my kitchen tea that I wasn't able to invite to the wedding, but I didn't ask anyone to buy me a present it was more I wanted them to be involved. Pretty much none of my friends were invited to our weddig cos we had over 100 people with family alone.

With a Tupperware kitchen tea the general way it's run is that the bride to be is the host, and guests can make a donation or buy a gift for the bride IF THEY WANT TO. It should never be a demand - I'd say the person writing the invites didn't think about how it would be interpreted.