You can manifest him back whether you contact him or not. There aren’t really any rules to this. I think it’s important to think about how it would make you feel before doing anything. If it feels good to contact him no matter what type of response you get (or don’t get), then there’s no problem with it. But if you hope it’ll go a certain way and if it doesn’t it’ll upset you and set you back, then just let him come to you. Which yes, can absolutely happen.