the anabolic window thing had a nice run during a time where guys depended on supplement companies for bro science. supp companies want you drinking a protein shake 'right away'.. this was further pushed when guys started injecting insulin into their asses during the 2000's to help them 'get big'
with the info we have today we know that is bullshit for those non insulin users. you don't need to get in a protein shake after a workout. in fact you don't need to eat either. the 'anabolic window' lasts 24-35 hours
optimally though when it comes to working out. you want to go into a workout fasted, then eat after. not eat first then workout
having said that if you are a skinny twig eating after a workout is a good idea, in fact eating more food any time during the day is a good idea. you need to eat more. so yeah