[Email invite] Double Email invite plan limit

I have 8 max users plan (7 assigned), I want to add a one new user to TWO new repositories (this user not register in system yet) - I will send invitation by email. When he assign first invitation by email - my plan full with 8 users. But when he try to assign a second invitation he get a message:

The owner of this repository (igorska) is already at their plan limit and will need to upgrade before adding more users.

The main goal that maybe would be logical when user register to system and have invitation that send to her email make auto assigned to projects. In my case with second project invitation was deleted and user assigned manually.