The first party games seem skewed to SP sad dad kinds of games, baseball and GT.
To add variety, they need a shooter. Whether it's KZ, a franchise from the dead, or a brand new IP, it'll add something fresh to shooters, where it's still dominated by Call of Duty, BF, and now a handful of F2P/BR kinds of games.
MAG had something going, but PS3 couldn't handle it. It also was weird with fake gun names. Make it modern, get real gun names, 60 fps, and it might be a good alternative to third party games. Wasn't a bad game when I played it. What hurt the most was that it barely ran at 30 fps. If you're trying to be Call of Duty-ish, you got to be 60 fps.
They should give Fighting All Stars another chance. Fighting games aren't so popular anymore, but SF, MK and Smash Bros seem to sell and do fine, so the interest is still there. Problem is they did it in a half hearted way compared to their SP AAA games.
Give MAG and another fighting game a re-try.