$4 million per month is actually relatively easy to do when you consider just how much talent WWE has on the payroll that literally hasn't been on television in 6+months or even years. also, likely half of that $4 million number will come from executive positions. there may be a few bigger names released (who are making $500,000+ and are on TV semi-regularly), but it will likely be a mass release of all the minimum to mid-range paid talent on both WWE and NXT rosters who are never used.
starting with NXT, there are literally dozens of talent collecting the minimum $40,000 per year who haven't been seen or heard from in forever. maybe a few will be kept, but the vast majority of those will be gone. then they'll start weeding out the talent in the $60,000 range who have been in NXT for 3-5+ years who really never stand a chance of getting on main roster television. you figure the same for the main WWE rosters where tons of talent are collecting $250,000 a year to just sit at home. a few will be kept, but most will be gone.
either way it sucks for all involved.