Still confusing seniority with status lists my friend! Calm down and actually consider the proposition with regard to your position on your status list only. Obviously there won't be 300 bmi types joining any single status list, there are about 170 Capt and 150 FOs.
What fleet are you on anyway? If you are a widebody then none of this affects you, if you are narrowbody then you'll move up the list to a better position than where you are now.