my boyfriend misses his girl bestfriend is that weird

so when i met him he had a girl bestfriend and a month after we met she got into a girls home. its been almost a year since she went in and ive looked through his phone a couple times and saw that he still sent her texts like saying how is she or when she comes out he wants to go eat lunch with her together or something like that, even though she dont reply. recently he heard that she came out so he texted again asking how are you. im afraid that when she actually comes out and they hang out again alone its just seems weird and i dont know how to feel about that. i know its probably normal but i just need some comfort :)