Whatever the exact reason, it definitely sounds promising. I doubt anyone would read a thesis unless they had a good reason to do so. Maybe he would like to collaborate with you in the future and is seeing if your style seems compatible with his. Or, yes, maybe he wants to see what you are capable of. And even if you know you're capable of more, to have passed your thesis is probably a good read to anyone who isn't sick to death of the topic. :p