How to know if he blocked me on whatsapp or lost his phone?

Hi
Last year i met a guy and talked to him on whatsapp. he seemed to like me. We do not have mutual friends. We met in real life and talked on whatsapp for a few months till i noticed his last seen time did not change for a few weeks and the messages i send him only have single tick. But i can still see his status, profile photo and last seen time.i decided i should forget about him and stopped checking his whatsapp profile .
After approx 5 months(early this year), he suddenly messaged me on LINE(an application similar to whatsapp but u can add contacts either using phone number or username) saying sorry that he lost his phone and thus my phone number and could not find me. i decided to check my whatsapp chat on him and realised he changed his profile photo and i can see his new last seen time, but my last messages to him still show single tick. Nowadays we communicate using LINE and he does not whatsapp me and i did not whatsapp him.I did not ask him how he found me on LINE but i presume by adding my username since he said he lost my phone number.my real first name is part of my username so it is possible he guessed it correctly after many tries.
I wonder why he did not find me on facebook. But he only knows my first name. He does not know my last name.he does not know my email address either.
The possibilities are A) he blocked me but later changed his mind B) he was telling the truth that he lost his phone and could not find me.
But i was checking his whatsapp profile for 3 to 4 weeks after he last whatsapped me. If it is true he lost his phone and then got the same phone number, it means he did not get new phone within the first 3 to 4 weeks which is so strange. But i know he has 2 phones and my contact is only in one of them, so maybe it is not strange...and he is very busy being a junior investment banker working long hours.
I am very confused...what do you think?