after reading abu muhammad's blogpost on wakeerah here is what i discovered.
Quote:
It is mustahabb to give thanks anew when new blessings come, by speaking words of praise. Gratitude for that may also be expressed by doing acts of worship, which includes offering a sacrifice or inviting people to a meal. The fuqaha’ have mentioned the kinds of meals that may be offered when blessing are renewed, such as the wakeerah which is made for a new home, or naqee’ah which is made on the return of an absent loved one, and hidhaaq which is done when a child completes a reading of the Qur’aan.
i had no idea these 'dawats' were mustahab.