The stress of being moved to a new environment with different cats will be enough to evoke another flu outbreak,he can pass it on to your others,this can be very expensive,difficult and time consuming (antibiotics twice daily,eye drop and cleaning),trust me,i had a outbreak from a new cat,infect 12 of mine!!cost me the best part of £1000 in vets fees at least
i would never take the risk again,i was careless,and it cost me and my cats
they have all since recovered,but my breeding plans have been put on hold,for a long time so i can be sure they are all clear,we had the calci virus,a mild one,but there are much worse,and i doubt a mild one would cause a cat to lose his eye.And my lot had 3 lots of antibiotics,6 weeks treatment per cat.