Having a tea invitation before the nikaah for those who cannot attend

What is the status of what has now become a norm where a girl who is making nikaah holds a tea invitation a few days/week before her nikaah. They say that they do it as their numbers for walimah are limited and thus cannot invite everyone they'd like to like neighbour's, friends, etc.

Is this allowed? What should one do if one is invited to such a tea? It's a simple tea where they serve savouries etc., no intermingling, however it is done for the above mentioned reason.