Hair loss is unfortunately progressive therefore if you replace your lost hair you may still lose your native hair. Usually we recommend to do hair transplant to replace the lost hair and start on a medical regiment routine to slow down the hair loss of the native hair.
If you don't understand your hair loss (diagnosis) and not plan your treatment accordingly, you may continue to lose more hair and look worse. We call this planning the MASTER PLAN.
Note: ARTAS is just a tool that cores the grafts using the FUE technique. It has nothing to do with results.
Focus your worry on picking the right doctor, not the machine. If you pick a good doctor, he/she can guide you in future planning and a comprehensive treatment plan.
This is a good question and only your hair transplant doctor can answer that after evaluating your hair microscopically when you have your initial consultation with him/her. Microscopic evaluation of hair (miniaturization study) is a great tool to predict where are you heading with your hair loss. Of course your family pattern and whether you take hair loss medication or not are other factors that can help your doctor know whether you will have shock loss (losing hair after hair transplant).
If you have a high risk for shock loss your hair doctor will recommend medications such as finasteride to prevent or minimize the risk of your hair loss after the hair transplant.
It sounds as though you are answering your own question here and no competent hair transplant surgeon should try to convince you otherwise. Learning more about alternatives that are designed to arrest hair loss will be helpful.
After replacing some of the hair, it is still possible that the rest of the hair could fall out. Your hair is still your hair and the same hair that feel out before the transplant. This is why it is best to consult your doctor and discuss your plan for the future. It is often that we hold off on a procedure and wait a little bit longer to see what other hair loss might occur. However, there are products out there that can help slow down hair loss.
Doing a hair transplant does not alter the course for your existing hair and these may still fall out. You may want to discuss with your doctor risks and benefits of propecia to try to slow down hair loss.
If the transplant sessions are not planned properly in consideration for the future, the scenario you describe likely will occur. Especially so since you are losing hair at a young age. Pose this question to your hair surgeon.
If you are balding, I would start off getting a doctor to give you the drug finasteride which can reverse hair loss in very young men. If you get to have a hair transplant and you are not on this drug, the risk of shock loss is very high which will accelerate hair loss in the rest of your inherited genetic pattern.