Upper molar implant abutment is visible - will this cause an issue? (photo)

I got the two implants (with sinus lift) at my upper right molars. The dentist did the sinus lift, bone grafting, and put the 2 implants at the same time. A month later, I had one of the implant migrate into the sinus that I had it removed with a surgery. However, the second implant has stayed in place but it’s visible (the abutment). The dentist who did it is saying there is no issue at all and it can be left as is. Is he correct ?